[MikeP]

Jonathan,
How deep are your pockets? What class of racing? How much do you value originality?
For ultimate performance the I guess best would be a one off honeycomb aluminium monocoque like Pete Thomson's car- light and stiff. Next would be an original style steel monocoque a bit heavy but very stiff. Next would be one of the many excellent replicas RF GTD MDA Southern RCR etc. Add any good quality rose jointed suspension shocks and brakes. Motors are the easy bit and then add any gearbox that will stand the power and torque of you motor. What you can do will obviously depend on the regs governing your chosen class. I have seen most of what is available and I would suggest you go and have a good look at running cars, talk to the owners and if possible try before you buy! Once you decide there are lots of helpful and knowledgeable people on this forum and in the clubs who know a lot more than I do. Get in touch with your local guys - I have found some brilliant people in the clubs.
Cheers
Mike