As someone else suggested, if you have a range nearby that rents guns, I suggest renting and shooting a few different pistols that you might want to carry concealed. Select the one that feels most comfortable to you, not what is comfortable to anyone else.
I have small hands, so I have a few of the pistols designed for concealed carry: two Glocks a Model 26 (9mm) and a Model 36 (.45), two Kahrs, both 9 mm, the MK9, and the MP9, and a Keltec in .32 caliber.
I prefer my Glocks for concealed carry, but I also carry the Kahrs or the Keltec at times. It depends on what I am wearing. Some styles of clothing, fabrics and colors will make it difficult to conceal the Glocks, because they are wider than the Kahrs and the Keltec. The reason that I prefer the Glocks is that the trigger pull is much shorter and I feel most comfortable with them. They are lightweight. The Glock 26 was my first semi-automatic, so I am very familiar with how it shoots. I bought my first .45 to carry about seven months ago.
I like the Kahrs, they are great pistols, my only complaint is that I think the the trigger pull is very long. The Keltec I use primarily when I am wearing exercise wear, because everything else is so heavy. The Keltec in .32 is for close range only. I don't have any experience with the other Keltec pistols, so I can't comment on them.
The most important thing is to pick a firearm that feels comfortable to you, comfortable in your hand, comfortable while shooting, but most importantly, that you feel comfortable with its features if you need it to defend yourself. I prefer the Glocks and Kahrs because all I have to think about if I need to use it, is aiming and pulling the trigger. Good Luck!