Cam. You can get that from alot of the major manufacturers, Crane, Isky, Comp, Clifford, some Aussie Companies, etc.
Gaskets. You can get those from any auto parts store.
Headers. You can get those from Clifford, or from Fordsixparts.com Id rather get the Pacemaker headers from Fordsixparts.com Theres also a header made by Hooker (longtube), I'm not too sure where you'd buy one of them but they are sold in various places.
Anything else?