Higher end programs might benefit from an expensive video card, but what you mention will not. That said, you might really benefit from building a small render farm, cause not only Bryce renders over a network, but 3DS, too. It has a network rendering client that can be installed on Linux machines. But, if you're going to use 3DS only for modelling, you don't need that. BTW, Xeon is Intel's CPU built for multi-processor machines. I know that Bryce can run its client on the second CPU, although taking the price difference and everything else into account, you're better off building another render machine than buying a multiprocessor one. 3DS can use multiple processors, though. Opteron is a 64-bit CPU, but we are still running 32-bit software. So, wait untill we get 64-bit Windows or something that will really be able to use the processor. Anything else, the advice you got is good: a strong CPU, LOTS of RAM and a usable video card, like GeForce 4600 or ATI Radeon 9700 Pro with 128 MB RAM.

-- erlik