For a 3D rig you should really buy a professional graphics card. I use FirePros in the workstations I sell. They work great and you can game on them too. I get 90fps in MW3 with a v5900. I also suggest a 3770k for your cpu as you will get hyperthreading which helps in rendering. I recommend Seasonic or Corsair for power supplies.
I've an option between MSI, InnoVISION, ASUS, KFA², Gigabyte and Leadtek graphics cards.
Because I'm working with slow moving graphics I don't have to spend so much but it will help a little I guess. I'm linking a different site as it would be the one I'm buying from (the Negwegg.com does not ship to my country)
Options:MSI N450GTS-M2D1GD5ASUS ENGTS450/DI/1GD3LEADTEK GTX550 TIKFA² 64TGF8HX6FXZ, GT640KFA² 64TGF8HX6FXZ, GT640GIGABYTE GV-N550WF2-1GI, GTX550 T
- this one is a bit pricy for me, but can do if i have tooGIGABYTE GV-N450D3-1GI, GTS450GIGABYTE GV-N430OC-1GL, GT430
etc... that's about the range I'm looking in...