I ended up ordering an LCD screen from Ebay seller EZ Elektronix who I purchased my digitizer from and was able to successfully install them together. I did not use a heat gun to re-assemble. As you can see below, the digitizer is mounted with double-sided sticky tape (0.3mm thick) which ripped in a few places for me. I tried to flatten out the tape as well as I could but there were sections of tape missing when I reinstalled the screen (LCD + Digitizer).
http://i.imgur.com/Ugllusu.jpg
Therefore, if your LCD and touch are working but screen is cracked (this was my issue), you probably won't be able to just replace the glass (part of the digitizer) because it's so difficult to re-use the LCD screen so don't need a heat gun for disassembly. You just need to pry the digitizer up around the border where the black tape is and your LCD will come up with it. You'll need to remove all internals including the battery to get at the screen's connectors.
When you go to reinstall, hopefully LCD+digi purchased together come aligned and sealed but in my case they were separate pieces. As you can see there's quite a bit of play between LCD and frame:
http://i.imgur.com/WFYO6LD.jpg
It's not clear how to align the LCD on digi:
http://i.imgur.com/0mD0BNp.jpg
So use my alignment for reference, difficult to see but you just need to use the stacked silver lines (conductive wires imbedded in digi) seen above and make sure LCD is not rotated. I lined up the top of the LCD with bottom conductive strip:
http://i.imgur.com/Vq4LNyP.jpg?1
Instead of the placement above, you will want to position the LCD 0.1-0.3mm BELOW the conductive strip on dig so you don't run into the issue of a few covered pixels like me:
a few pixels hidden by digi
Note that if this happens to you, the touch still lines up with what I see on LCD because it's so close to the correct placement. I wasn't asked to re-calibrate the touchscreen but there may be a way to do it, for me I just re-assembled and everything worked as it did before.
Also, I used electrical tape on top and bottom only and it holds fine, but I did not install the "light bar" whcih must be what's pictured below. It's simply a clear piece of plastic w/ two light sinks (tabs) however I don't know where the light source comes from... So my "recent, home and back" buttons don't light up, but they are still visible in the light. The button touch works fine w/o light bar. To remove it from your old digi, a heat gun is not necessary. I just used a razor blade and it came off w/o any trouble.
http://i.imgur.com/F8Ky2A8.jpg
I don't know if there is cured adhesive on the digi waiting to be heated, but I did run into a minor issue and I'm not sure if there's some oil (I did use neoprene gloves when installing so doubt this is the case) between digi + LCD or if it's just because it's in the center but the touch in center is a little finicky:
http://i.imgur.com/dmMn25t.jpg
I purchased an otterbox defender (heard the commuter didn't fit the phone very well). Note that the defender has a built in "screen protector" which is a reasonably thick piece of plastic. That piece of plastic makes the touch
much less sensitive and you'll be frustrated just trying to unlock the phone, remove it immediately! I used to have an ArmourSuit MilitaryShield screen protector which was on phone when it broke and it didn't effect touch negatively. Get this w/ a phone case if you're worried about the screen. I already dropped my phone on its corner onto concrete and it didn't break, phew!
http://i.imgur.com/HsbTIDh.jpg
It's huge and the phone feels bulky in your hand when you remove it (feels so sleek w/o it!) but it's $30 + 5 min vs. $160 + hrs.
http://i.imgur.com/JHsyfxO.jpg
Good luck, let me know if you want high res or other photos.