Computer Specs for 3D rendering.

[Zuban]

Been doing a lot of 3D stuff on my GTX 570 OC. It is very good, also I had the luxury to compare its perfomance with Quadro 4000.
From personal observations: I've noticed the difference only in how quick model picture re-draws on the screen in wireframe mode with big models/scenes. And it was a matter of seconds on models I worked with, as Quadro card calculates and outputs results to the screen a bit quicker. Also it wins you a few minutes in the actual rendering stage. Downside is quadro sucks for gaming.

If you choose gaming Nvidia card, just make sure you have 2GB VRAM on it for textures, that will be plenty for learning and playing around with high quality textures. You can follow SheepBeasts advice and look for GTX 670 it will deliver gaming and comfortable 3D development.

one important thing i've discovered and i dont know how this affects other cards but with my gtx 670 when using 3d software i found it very slow when switching between models that were to large for all to remain in memory at once, so i fired up gpuz and watched the sensors and the memory controller was running at 125mhz or something, and the gpu clock was also low, so the card was idling really rather than detecting there was a 3d application running or however it works, I now apply an overclock on startup using msi afterburner that is really just stock clocks +5, this forces the card to never idle down and the difference is immense like less than 1 second instead of 5 to switch between models. I wonder if this is the sort of thing that isnt a problem with the proffesional cards.