SIG and HK are both excellent.
If you can handle the .45 DEFINATELY go to that round. It is a stopper. If you get the .380 you will have to empty the magazine and hope for the best.
I also recommend you check out the Kimber line of compact .45's - superb out of the box,. Anything else and you need to spend ~ $200 for a good gunsmith to work the action, etc, for you.
http://www.kimberamerica.com/CDP_Series.htmIf you get the .380 you will have to empty the magazine and hope for the best...Good to know. When I bought a shotgun, the clerk wanted to sell me bird shot so it wouldn't go through walls. I told him I wasn't worried about that, it needed to go through the door as well as the person. He seemed shocked that I said such a thing!