Do yourself a favor and go with the Glock 36 Slimline.
It has the slimest profile of any .45 on the market. It takes single stack mags, but you can get extended mags for home, and the stock 6 rounders for CCW. It was an easy chose for me when I bought my carry pistol.

I agree with cooter....Glock 36

I'd go with the more modern double-action unless you are just used to the single-action-first-shot and are really comfortable with it. Remember, this involves carrying shell-in-chamber hammer ready to fire or hammer down and you have to remember to pull it back, or chamber empty and rack the slide. In an extreme and stressful situation it is better to just pull the trigger and start the firing process.

H

I personally prefer a .38 or .357. No fumbling around at zero dark thirty when someone wakes you as they break into your home. Just grab it and start squeezing off rounds. No safety to fumble with, no trying to remember if a round is in the chamber. No jamming.

I would prefer the H&K USP Compact versus a compact M-1911 type pistol.

Also check my answer to your other related question.
http://answers.yahoo.com/question/index;_ylt=AjItQczgGJx01uDkitxKJBpQxQt.;_ylv=3?qid=20080229043745AAsDA5r

You can't go wrong with a 1911. STI makes a great compact 1911 called The Escort. The Springfield EMP is a 9mm compact 1911 that received Gun Of The Year honors.