Hello Pibb. Personally I sometimes wish my dept. carried the Glocks as a primary handgun, but I carry my G36 .45 as a backup/off duty. :). We carry the Sig P220R .45 (actually it is shooters choice) we also have the option to carry the P226 in .40 but needless to say about 90% of the department went with the .45.
If you are going for strictly concealed carry I would look at the P239 (it comes in 9mm, .357SIG, and .40. Also the P229 in .40 and .357SIG really seem to be popular but personally I find it to be rather heavy. A big + to buying a Sig in .40 or .357SIG is you basically have two calibers in one. You can use the same magazine but all you have to do is purchase an extra barrel. Just swap out the barrel to the caliber you want to shoot and not you have two choices.
The P220 .45 is a single stack magazine and overall is fairly thin so concealing it may not be a problem for some but man is it a nice shooting pistol. Good luck and I hope this helps a little. Stay safe!