Hope this is not too little, too late, but my 2cents

Fur is right; buy a vetra, you wont regret it.

why don't you go with an amd dual core?

anyway, the general spill if your building slave machines....aim to spend about 50 bucks a component(maybe a bit more on a cpu), and get the best component you can for that 50 bucks. For 50 bucks you should be able to get a better 3d card...(I've heard that you should always buy mid range + card (eg, for example, 8500+) I have no complaints about my 8500's...but then I never tried a 7200. /shrug. anyway, 50 dollars a component should comeout to about 400 bucks a comp...(not counting a monitor) Also, do you really need a 500gb drive in each of theslaves? I bought a big box of 40 gig hard drives pretty cheap awihle back....(I don't remember the exact price, but i think i got them for 25 dollars apeice or something similar.) at any rate, a 40 gig will hold windows xp + wow. tho this might not be true for vista or windows 7...but 500 gigs is definatley overkill unless youplan to do sometihng with the machines other than play wow as a slave...

it might be cheaper to just sit the monitors on boxes...rather than buy stands. I personalyl got a 200 dollar triple monitor arm, but in retrospect I think I would try building a stand...if stand is the appropraite word for sometihng made out of MDF or wood that you mount monitors to =0.

add in 300 dollars for a vetra, and your in business.

When I went from 3 comps to 6 comps i think it cost me about 3k....but that got me 6 LCDs, 3 new comps from nothing, a vetra KVM and multiplexer, a coupla x-keys gadgets, and a ergotron triple arm.