You can try this place for spares they are able to get hold of quite an extensive range:-
http://www.tamiyaparts.co.uk/tamiyaparts/tpx/kyosho.htm
Your going to need part numbers so these might help with that:-
http://www.retromodelisme.com/manuel...zx-kyosho.html
http://www.retromodelisme.com/manuel...-r-kyosho.html
Repro ZX bodies from this guy:-
http://www.tamiyaclub.com/trades_model.asp?cid=48650
But to be honest by the time you price up all the parts you need at the price of Kyosho stuff at the moment you might be better putting the one you have back on the bay cutting your losses and trying to get hold of a complete car in good runner condition from a reputable seller. I will pm you a link to one that is for sale at the moment that might be worth investigation