VideoGuys publish a DIY computer guide and they're up to their 9th machine which is based on the i7 chip.
I'm persuaded to go with a dual xenon hexa - core machine. And 24GB of RAM.
And I want the computer to be in a rack-mount case. See that rack behind me? The one with the headphones and Purell? I want to put the computer in the bottom of that rack. That means wireless mouse/keyboard in likelihood I should think. And a 10-foot DVI cable.