The Quadro 6000 looks interesting, right after you've pulled yourself up off the floor.
Is it all about render speed then? I have played about with production resolution stuff with Maya, and I had to use networked computers as I render farm just to get to get 30 seconds in a day. I was using render layers too (shadow, motion blur etc) so the render time would have been considerably less if I'd just exported the baked movie.