I would doublecheck with a reseller (or autodesk, but I find the VAR"s are far more helpful), I know of a few Autodesk applications that are capped at 4 cores. Unfortuantely the products I am more familair with are on the Civil engineering side (i.e. Revit, Civil3D, etc), but I'm pretty sure 3DS will sue more than 4.
Looks liek Adobe Premier will use 8:http://forums.creativecow.net/thread/3/880647
For what (it sounds like) you are looking at I would make sure to get a 64 bit OS with tons of RAM (8GB maybe, I'm assuming your projects are complex).