beside dual core g5 and fcp what else is needed
 

a good post production set up under 6000$

not "necessary" but extremely worthwhile...
 

Two good displays. Preferably widescreens. I suggest the Dells.

Quality audio monitors if you are going to be doing any amount of mixing.

An external color correction monitor.

Additional internal or external harddrives.

A Contour Shuttle Pro. (this is more of a luxury than the other items I've listed)