Scanr you might get some better advice if you let us know a little about your shooting experience. What guns have you shot, what did you like about them, what did you not like, how recoil sensative are you, how are you planning on carrying it concealed, ect. This will help us identify guns that might fit your needs.
Here's what I carry as a left-hander. Remember this is just my list of common carry pistols, not all that I shoot.
1. Smith and Wesson 642 snub-nosed .38 Special
2. FM High Power Detective model in 9mm (3" slide and Cylinder and Slide hammer/sear)
3. Kahr K9, also in 9mm
I carry the High Power about 90% of the time, It's an Argentine copy of the FN frame with a 3" slide. I've had to change the hammer/sear to Cylinder and Slide parts to cure a case of hammer bite, and had the magazine safety removed, but it's stock otherwise. The K9 is a good little 9mm pistol, but a little heavy for the capacity. I'd check out the P9 if you are going to consider it. Finally the 642 is my pocket carry option for when I can't dress to accomidate an IWB or shoulder holster.
I'm currently evaluating a Springfield XD45 Compact for carry. Before I do that, I need is a good IWB holster, discrete single magazine carrier, and to run a couple hundred hollowpoints through it. After that I'll be comfortable carrying it.
Finally, I always "slingshot" the slide to return it to battery. This means that I can use the same motion for different pattern pistols, also I feel it gives a little more impluse when chambering the round. Hope this helps.
Tex