You need a good carry gun. Check out the Smith and Wesson M&P line if you havent already. They have a new model out called the M&P Shield thats a single stack and would be very easy to carry.
http://www.smith-wesson.com/webapp/w...1_757781_image
After carrying for about 10 years now I have found that a smaller more comfortable gun will more likely be carried than a big heavy gun that you grew sick of carrying.
My list of great carry guns are:
Baby Glocks
Compact M&Ps
Shield
Snubby Revolvers from S&W or Ruger
I would personally grab a 9mm if I were you due to the lower cost of ammo and less recoil. Buy some good ammo like 147 grn Federal HST, 147 grn Gold Dot or 124 grn +P Gold Dot.
The most prolific gun used by police in America is the Glock, whith the M&P gaining quickly. There is a reason for this. They are tough and reliable which is what you want in a carry gun. How good it looks or how cool it is doesnt matter in a gun fight.