As in an above post I went to a 637 Smith and load it with +P Small, accurate and not hard to get a second shot off. I have one of those cheap Blackhawk pocket holsters and it's so light that you can almost forget it's there after a few minutes. And a 38 or 38+p are pretty good in my opinion anyway.
I don't think I's want to try a pocket 45 on for size. The 3" is about as small as I wan to see them and I don't see that as a pocket pistol.