You really can't choose a gun until you have shot it. Your best bet is to look for a pistol range that allows you to rent guns. They usually have a pretty good selection of rentals to choose from. Either that or find a buddy that has some guns that you could try.

While I was still stationed in Cali, I tried out a few handguns at an indoor range close to base. That is how I made the choice to buy this:



Not only that but H&K is a well known, quality brand. Not cheap, but you're definitely getting your money's worth. I am also planning on picking up one of these in the near future:



My favorite pistol from CS

 

find a local range that offers rentals and try out some different guns to get the feel for what you find comfortable and what feels good shooting

from there look at what you liked and break them down by price as to what you can afford.