I agree with the above post. I'm a bit prejudiced as my first pistol ever was an 83 in .380, and (I know we've all heard this story before) with good ammo I don't think that the .380 would let you down.
As for the CZ vs. (what I believe is a) Kahr, well, I know from experience that the RAMI is a sweet little shooter, and is comfortable for IWB or SOB carry. A pocket pistol it is not. And for what little it's worth, I would go with the 9mm unless you have had enough time in with the .40 S&W to know it's what you want. It took me a few months, but I decided that I despise that round.
In my opinion, and YMMV, the CZ is made to shoot, and shoot bloody well, while the Kahrs are made to wear comfortably all day long. That may be what you need. You hope to God to never have to use it but always have it, and the Kahrs are beautiful little sidearms.
But what do I know? When I carry I switch between my 75B (full size, of course) and my GI 1911 (again, full size). I'm "fluffy" enough to pull it off.