You can't go wrong with an S&W Shield. After trying to lug a full sized 1911 I found that full sized carriers are just fooling themselves. I've been running the much much lighter PF9 for a while now and had some early issues . After a "fluff and buff" plus all metal replacement parts, I'm closing in on the 2200 rounds of no-issues mark. You'll pay a premium for the Shield but I'm guessing you want minimal fuss and reliability.
Do NOT skimp on your holster. You may have to make some wardrobe changes if you like to wear tight shirts. A good "tuckable" holster should be comfy but also allow you to still wear t-shirts and polos. The Crossbreed "Supertuck", Desantis Intruder, and Galco "King Tuck" are all really good holsters. My dad runs a Remora holster but it's voodoo and my brain refuses to come to terms with a clip-less holster. Remember that you'll need to take a long hard look at your wardrobe. Some changes may be in order.
http://www.youtube.com/watch?v=DaWyS3cTMHA
Practice, practice, practice! You need to be able to draw, aim, and shoot in a smooth manner. Do it from an outside the waistband holster or drop leg is waaaay different than drawing from concealed. The last thing you want to do is have to be fumbling with a shirt or being surprised at how entangled you can be by your clothing. Practice with no ammo and figure out your weakness and where to improve. Switch to live ammo and see if you can hit anything. Compact pistols are snappy compared to full framed handguns. You'll need to double down on getting those follow up shots.
Practice a few times with the ammo you will be using. Make sure the ammo you run will cycle properly in your pistol. If you're smart, you'll go for +p hollowpoints like Golden Sabers, Gold Dot, or Ranger-T. You've already determined that your life is in danger if you have to deploy the weapon so you want to do the most damage necessary and stop the threat if you do fire the thing. Expensive but then what's a $0.50 more when it comes down to you or the bad guy? Also remember, if it's worth shooting once, it's worth shooting a few more times. The idea that one shot is going to suddenly make them stop and fall on the ground is patently false. You might get lucky and hit a CNS component, but the chances are you'll miss even at close range let alone hit a part that will incapacitate the attacker.
Wear the thing as much as possible. You'll start out as a pile of nerves always wondering if you're "printing", if the pistol will fall out of the holster, or that the police might suddenly target you for some odd reason. It will take time to get used to wearing it. You'll never forget the weight stuck on you hip, you'll just be more used to having it there. Certain actions and movements you need to do (like sliding into a large chair with arms but observing that you don't let the arms catch the grip and yank out your handgun) will become easier and you'll end up doing them subconsciously.