Mac video card upgrade for 3D apps?
 

Hopefully this thread will find some viewers. As I've stated in other threads, I'm learning Blender. I'm doing this on a Mac pro 8core, with 26gigs if ram. It still has the stock 2009 video card, which doesn't allow for gpu rendering. So I'd like to upgrade my card, and wondering what Mac pro users here might be using? Can I goto the 5870, and be good for 3D apps, or do I need to go to something like a quadro?

Thanks
Jeff