Two 680 or Quadra 5000?

I mostly use my system for c4d (and other 3d apps) and After Effects. I also use VRAY which can really go to town with CUDA.

Which would you go for?
Two 680
Or
Quadro 5000k (imminent release)

My initial thinking is to go for Quadro 5000k and then I can later add a Tesla card to give me a Maximus configuration.

I'm not even sure if the Maximus config works on Mac...which would push me towards Bootcamp.