Cheap 15" wheels for a Cobra?

I want to go to a 15" wheel for the track. I once borrowed a pair of 15" wheels from a guy and they fit over my rear brakes. I didn't get the brand name of the wheels though. They were all black and looked like ones they use in NASCAR. I don't want to break the bank with some Weld wheels so are there any cheaper alternatives? I would like to get at least an 8" width.

Thanks,
Gabe