First off, I think you will enjoy the revolver most if you stick to the reputable names (Smith, Ruger, Colt, etc.). I personally keep a S&W Model 19 .357 4", and it is a freaking tack-driver. I love that thing loaded with 38 Specials, and so does my fiance (who shoots it better than I do) who is half my size.
As to a .45 ACP revolver, my LGS has a Smith and Wesson for sale for about $600. I don't remember which model, but its a classic model. If you're interested, you can call him during business hours (Tue-Sat) at 812-725-1911.