Dont forget that when you buy the scope you'll need to have the mount as well. You might be able to find what you're looking for on ebay as well.
Scope mounts fro the K-frames require that you remove the rear sights if you have a revolver that has adjustable sights on it. Depending on the model of your wheelgun you might need to have it drilled and tapped for the scope mounts too.
Swift is a pretty good pistol scope, and they sell mounts to fit their scopes to many gun models as well.
I'll look around and see if I have a scope I might part with. I'm not sure if I do or not. If I can find one I'll give you a PM otherwise I don't have one.
Best wishes for your search. They're easy to come by, but pistol scopes don't come cheap by the time you add the mounts and modify the pistol if that's necessary.