Hi-tec do a good servo, can't quite remember the model number but I think it is HS81 or something like that. Have a look on the UK micro forum:
http://www.uk-microrc.co.uk/forum
I know that the FTX Pro alloy shocks, ball diffs, steel drive(swing) shafts and front alloy hubs are normally used. Also get some gecko foams, they last ages and grip well, even without additive.
HTH
Mark