Any Glock is fine, easy maintenance.
Since you mentioned .45acp, check out the Glock 30.
It's compact, similar to the G19/23 models, so it's concealable but it carries 10 big rounds.
You can go smaller with the G36 in .45 if 6 rounds will be enough, or you can go larger with the G21 if you want 13 rounds.
For the best compromise in .45acp Glocks, you can put a 13 round G21 magazine in the compact G30, and an optional grip adapter makes it even nicer. Go to a range and rent some, see how they fit your hands.
Or you can buy a G30 and use G21 magazines. Glock mags are interchangeable.
I'm left-handed, so bear with me. I prefer Rugers in .40 cal. They're easy to handle and are ambidextrous(sp?), and they pack a wallup of firepower...