Bought Car/Have questions

I recently purchased an 20yr old Rocketech that I am converting to an autocross car. Trying to figure out were to get parts seems to be difficult. I am going to change over the final drive but trying to figure out where to get the pulleys (it is a belt drive with a two piece final drive/aluminum with a six bolt pattern) and looking for one on the internet is not proving very helpful. Any ideas?

Also I was looking for brake rotors (so I know before I need). I was looking on the Willwood website and could not find anything close to them dimensionally. Was wondering, are they like rotors off quads or motorbikes? Even looking at the Douglas Wheels page wasn't very descriptive. Is there a place somewhere that specializes in these cars that can give me better insight where to find the parts I need?
:confused:
Thanks

Bought Car/Have questions