Almost done building my new rig - AMD3800+X2 / ATI X1900
Should smoke those little proteins.
Will the MB have 2 CPUs? The new SMP betas are pumping out about 1,000 ppd for every system. Add in the GPU clients (not sure if they will work together), for 600 ppd, you could have a real barn burner.
The GPU can run as fast as possible, will use a moderate amount of CPU just for housekeeping, and the CPU probably can run a second core at about 25% - 40%.
Just be sure not to load Office, any games or other useful stuff. You are spending all this money for F@H. ;)