Best Graphics Card for OpenRoads ConceptStation?

We've recently started utilizing OpenRoads ConceptStation heavily, but using our 2GB R7 250 GPU is taking quite some time to render anything. Money is not an issue, I just need to know what Graphics Card is best utilized in this process. If had a card with 11GB of VRAM would it take full advantage of that? Do the Quadros have an advantage over the GTX series? Does CUDA core count matter?