Road bike back wheel with gears... Anyone who can help?

Thanks rodabod. the bike is a Cannondale S R 400. I'll put the wheel and a pic of the bike frame and see if you can get anything from it- wont do it so here is the link

Ok, assuming it's the same bike as in the link (ie. roughly the same year), then it appears to be 7-speed. You can check by looking at your shifters.

I think you should just buy a decent wheel with a 7-speed block. That can use either type of gears pictured above, ie. "hub and thread-on freewheel" or "freehub and cassette". The latter is usually preferable.

I'll have a look and link to anything I see that looks suitable.