Easy: Smith 3" M60. You get:
Concealability (disappears in a OWB pancake holster)
Stainless Steel
.38 Special (to include shot shells) or .357 capability
Adjustable sights (yep, handy on a 3" gun)
It's the one that always accompanies me in the field. Truly versatile.
Watch GB and pick up a lightly used Smith 686. 6 or 7 shots with the best trigger around. The GP100 would be my second choice. 4" in either model would suit you quite well.
Here are a couple nice 686s that would work:
Smith & Wesson 686 4 inch : Revolvers at GunBroker.com
Smith 357 Magnum 686-1 4 inch Stainless : Revolvers at GunBroker.com
You can score one for <500 in a week or two if you watch the auctions and don't get into a bidding war. I've seen several go for $480 in the last couple weeks.