First let me say I don't see a big difference between PT4 and HM2.  I have PT4 so I'm familiar with PT4 and prefer it, but if I have HM2 I'm sure I'd prefer that.  But I don't think that's what your asking.  I can give you some insight for everything else since I have it all pretty much.

The very best solution would be PT4/HM2 plus the Bovada Catcher from Ace Poker solutions.  You'll not only get a customizable HUD but you'll be able to review your sessions easier and search and filter for specific situations.  If reviewing and reports are you thing I would recommend getting the Bovada Convert (also from Ace PS) which will convert Bovada hand histories into PokerStars format allowing them to be uploaded …..ns/#p56947

This is the best, but it's also the priciest.  The small stakes PT4/HM2 license is $99 (+$70 if you want the big boy license for buy-ins over $20), the Bovada Card Cather is $40 (+$20 if you want cash games too) and the Bovada HH Converter is $16 (+$16 if you want cash+omaha).

The cheaper option is one of the Indicator products, which there are 2 of; Holdem and Tournament.  If you ever plan on playing any cash I would recommend Holdem Indicator since it works for both cash and tournaments.  The only thing Tournament Indicator has over Holdem Indicator is it shows how many BB you have left (and M as well).  That's nice to know, but and estimation is usually good enough and I have simple spreadsheets I can use if I ever felt that I couldn't estimate well enough.  Not having the flexibility for either cash or tournaments is huge though.  But if you never plan on playing good amounts of cash then just do the TI.

The price of HI or TI is 79 pounds or quids or whatever.  That's about $130.  However it says if you deposit $50 on Sportsbook.com (which the actual address is Sportsbook.au) you can get it for free.  Which is wierd because when I navigate to the poker section of that website it blocks my “juristiction” or something.  I don't get blocked from the HI/TI affiliate link.  And HI/TI says the do take US players.  Wierd.

So my final recommendation – if you can deposit $50 in Sportbook.com and get TI/HI for fee then do that.  Even if you'll never be able to withdrawl that's fine, you'll just be paying $50 for the HUD.  If you have to pay full quid for HI/TI then it's better to go with PT4/HM2 + the card cather.  

PT4 has a free trail but it's not fully functional I think.    Every other program I mentioned is fully function during the trail.  I would recommend trying each for a couple days.  Do something like HI for one weekend, TI the next, then HM2/PT4 + card catcher after (don't forget to save your HH so you'll have a decent sample incase you want to try the HH converter).  Get a feel then decide where to commit your money to.

Well it seems that PT4 will allow you to import opponent hole cards (through the converter) while HM2 won't (except for older versions).  If that's the case then I think PT4 is the clear choice of you.  If not for that then it's a toss up.

Another thing to consider is that the Indicator products do keep a database.  You'll be able to keep long term stats for player on Merge, but they will be very limited (vpip/pfr, steal and fold to steal, cb and fold to cb, went to showdown and won at showdown, AF, net total winnings and # of hands).   It does have a session reviewer/hand replayer, but you won't be able to filter out for spots or do any reports.  But it does keep stats on everyone.

Another thing to consider is with the Indicator products your license is only good for one computer. About 6 months ago I got a new laptop and had to email them to activated my license. Recently I upgraded to an SSD (which is freaking amazing btw) and had to get a new license again. Now I’m thinking about building a gaming PC that I would use for poker too, but if I move the license to that machine I would have to move it back to my laptop when I go visit family during the holidays then move it back again. Pain in the ass.

I just confirmed with Ace Poker Solutions that they’re product license are good for 2 machines, just like PT4 and HM2. I’m thinking about getting the card catcher just so I don’t have to deal with moving the Indicator license.

As far as my rig about 2 years ago I got a piece of crap laptop for $300 at Best Buy.  It had a Pentium B960 with 4gb of RAM.  I had it connected to a 1080p external monitor, but sometimes I used it in dual monitor mode.  Since I'm on Bovada the max tables that will fit on a 1080p screen is 6 that is the most tables I've used (occasionally 9 tables with the extra on the second monitor).  The HUD I used was the Holdem Indicator, but I did have PT4 installed but only used it to track results and run reports.  I've never had any issue with it.  The only reason I upgraded was because I wanted on with a 1080p screen (so I can play 6 tables while traveling).  I've never had any problems running other programs too, usually streaming Netflix towards the end of a session when I'm in one or two tournaments.  I can't say for certain that I could do that many tables with PT4 + card cather instead of HI, or that 20 tables would bring everything to a screeching halt, but I'm pretty sure it would be able to handle it.  But I wouldn't go any lower than that.  For example Celerons would be out, as well as the low voltage versions of Pentiums.  I have no way to qualify this but I think if you search for a processor on …..hmark.net/ and it has a score of 1800+ that would be the bare minimun.  And I'm sure any modern desktop processor that retails for more than $70 would be fine too, although I would recommend Intel over AMD.  So in summary you can get away with a mobile pentium (just make sure its not a low or ultra low voltage version), but to be safe go with an i3+.  If you have a set up really old it might be worth it to upgrade.

What I have now is a laptop with an 15-4200u 6gb RAM, and I didn't really notice a difference for what I use it for compared to the B960.  Recently SSDs have become insanely cheap so I replaced the HDD, and I notice a huge difference.   My machine feels so much faster.  It boots up in about 10 seconds compared to over 90.  Programs load instantly.  I would highly recommend one.  PT4 says the bottleneck is usually the hard drive and normally an SSD upgrade will give you the best performance increase.  

My new laptop came with a 750gb hard drive and a DVD drive, so here's what I did; bought a Samsung 840 Evo 256gb SSD, transfered the contents of my hard drive onto the SSD (the Samsung software made it stupid easy, then replace the hard drive with the SSD.  When booting up with the SSD it was exactly like my hard drive (some programs and such).  Then I bought a hard drive bay designed to go into the DVD drive bay (for $20), replaced the DVD drive with the hard drive bay, then installed the old hard drive into the hard drive bay.  Now I have the best of both worlds, a 256gb SSD and a 750gb 2nd hard drive.  

As far as the apps, I here NoteTracker is a poor ripoff of NoteCaddy.  TableTracker and Table Scanner are essentially the same thing but it's not free, it costs $15, $25, or $35 a month depending on stakes.  The equity calculator is just like Poker Stove but with Omaha.  The ICM calculator is very basic, not really much better than this site …..cmcalc.php.  It's possible I just don't know how to use it, but I'm sure ICMizer would be much better for studying final table ICM decisions.  Leak Tracker isn't anything special.  It just goes through some of your stats by position and tells you if you are in the range that winning players in your stakes are.  For example it says I fold to flop bets too much.  That doesn't really help my game much.  Just about every other stat is within the 'winning player' range.  But none of those things really apply to me since almost all of my play in on Bovada.  No player can use any of those tools there, and I kinda like it like that.  Sure you could use it them on Merge, but is there enough traffic on Merge to justify the extra costs?  Could you really pick and choose the tables you want to play at, or would you normally just play whats available (like Ultimate Poker in Nevada).  On Bovada you'll never get enough hands where the advance stats or tools will be useful at all.  I recommend PT4 only because I can import opponent hole cards and I'm pretty sure that cant be done on HM2 (unless you use and older version).