there website isn't all that great..but they both carry alot of parts..
you're best bet is to email them both with the parts you need.
Champs will probably have the better price...
also.. I may have a set of Delrin diffs and front one-way for the F201.
and maybe a body or 2.. clear and unpainted... I no longer have my F201 but still have some stuff left... I'll let you know what I have...