My bro in law sold his RS200 replica (RS Automotive) yesterday as it happens and it about to buy another one!! Good fun and you dont need a silly high spec engine to make them go well due to the weight etc.... Hardest part is choosing gearbox/linkage, he was going to go the porker gearbox route but worked out too costly so went the Renault 21 box which worked well (most common route)

there is a forum i think, www.rs200.org with info.

Chris