Thanks for the input!
Yes, cost is a factor. I'd love to have a Broomhandle, but even the Astra copies are too much. I think the guy I'm working with on this thing would prefer the look of the revolvers anyway ( why I was asking about revolvers, not auto loaders ). We're also looking at using BP loads for their smoke effects, and I'd rather not foul up a vintage, expensive autoloader with BP. The HR and IJ guns look like good cheap props for this.
But if the old single action guns would not be entirely out of place for this location and era, I might just go for an 1875 Outlaw, as I've been thinking about getting one for myself regardless of where this project goes.