Need help please! (3d animation based)

Im building a computer for my Boss, but i really havent made a computer spec'd for strictly 3d animation aimed stuff..

Im thinking of an i7 2700k
With an z77 Extreme 4
and 8gb ram

But what graphics card should i go with?
Should i go with a workstation graphics card.. or what?
I was thinking maybe a gtx 460 or maybe the new 660 would be plenty?


or maybe should i go with AMD?


Please suggest idea's asap! Thanks for any help