As far as I know, the rotary engines karts don’t actually compete with others so much. My basic suggestion would be to persue this project in order to develop your product and learb about our great sport while doing it.
As for the chassis. I have been dealing directly with the PCR factory since 2000 and can help you a bit. You will find that almost everything for that kart is no longer available. The Jaguar was likely produced around 1997. Brake pads are not available and would need to be re-lined locally if you can find that service.
I may have steering columns and spindles here and there.