MY Father In Law has a person that he knows that is a gunsmith. He sell STI Guns. I got on the website and saw them, but as I have never known this brand before, I am not familiar. It does seem extremely thin, and nice and concealable. It is offered in 9mm and .40 cal.
It's at: http://www.stiguns.com/
You'll need to scroll down the left side to look for "Complete fiirearms", and look for the LS series (LS 9/LS40).
The only thing that I could see tha tI might be a little hesitant about is the number of rounds the magazine can carry, and that the slide does not lock once the last round is ejected.