I think the cheap way to go today is the Scat Pack calipers or maybe something from a GM car. Not really sure about the SP caliper though as they have a different construction than the Viper calipers you have, but they seem to run them on a lot of cars.
I have a single radial mount rear caliper for a later Viper, but don't want to spend the money for another one and a bracket is much more involved. Everything so far has been easy to get cut out of a plate on a laser or water jet, but that would require buying a kit or getting a machine shop involved.
I started as a drafter and love layouts for this stuff. Unless the base for the layout is wrong (see above).
