This is total different direction, but if you have alot of single-action experience why not get a smaller cowboy gun, like the Colt Lightning Revolver reproduction that Cimarron makes? I would wager 99% of the fights you're likely to get into running your coach could be settled with a sixgun.
As far as autos, if I was going to get a .380 I would probably get a pocket gun like the Ruger LCP or the Kel-Tec P3AT. Not sure how much fun these guns would be to shoot as a plinker, but you can take them anywhere.
If you want a larger gun, and are still considering .380 then a Walther PPK or a Beretta Cheetah would be a good choice, although a little pricey (especially the Beretta). Everyone give me an amen if you wish they would make both these guns in 9mm!
Like some of the other here, I think stepping up in power would be to your benefit. I don't think 9mm is anemic like some people (although if I knew I was going to a fight I would carry a .40 or .45). I think a 9mm will serve your purpose well, and would recommend you look for a used Glock 19 if you are wanting to keep your pricepoint down.
Good luck and good shooting.