I'm specing out a rad workstation that screams, and graphics cards are expensive.  Is there a point of diminishing returns with graphics cards, or is it best to go all out?

Thanks,

Cliff

ATI Fire Pro V4900 1GB

NVIDIA Quadro 2000 1GB

NVIDIA Quadro 2000D 1GB (2 x Dual Link DVI)

NVIDIA Geforce GTX 670 2GB

ATI Fire Pro V5900 2GB

NVIDIA Quadro 4000 2GB

NVIDIA Geforce GTX 680 2GB - (Special Order)

ATI Fire Pro V7900 2GB - Extended Lead Time

ATI Fire Pro V8800 - Extended Lead Time

NVIDIA Quadro 5000 2.5GB

NVIDIA Quadro 5000G 2.5GB - Extended Lead Time

ATI Fire Pro V9800 - Extended Lead Time

NVIDIA Quadro 6000 6GB - Extended Lead Time

NVIDIA Quadro 6000G 6GB - Extended Lead Time