rawrdinoah
here's a bunch...

fsfreak07
go to hobbytron.com or just check google.

J. Green
Sorry to say, but spring revolvers are actually pretty weak in terms of power (Gas revolvers are another story, though). If you really want one, though, I would suggest the UHC revolvers. The only place I could find them would be at the link below, towards the bottom of the page.

flyinggoldfish
You won't! Spring revolvers are hopelessly underpowered, usually about the 0.5J range (approx 220 fps with .2g ammo). This is down mainly to the fact that in a revolver there's no space for a decent size spring and piston. Most stock AEG's have about 1.5J of power. Gas revolvers, on the other hand, can be quite powerful though considerably more expensive..