If you want to go with a Core i7 Six Core CPU which is LGA 2011 you will need an LGA 2011 motherboard.
I just priced these parts and it is almost hitting your $500.00 amount. That doesn't include a hard drive, blu-ray drive or case and fans.
ASUS P9X79 ATX LGA2011 X79 - $256.12
Corsair Enthusiast Series TX750M Modular 750W - $116.12
Corsair CMZ8GX3M2A1600C9 Vengeance 8GB 2X4GB DDR3-1600 CL9-9-9-24 - $52.37
Total: $424.61
I honestly recommend going with an LGA 1155 build. A core i7 2600K or 2700K should do fine for rendering and gaming. That will save you about $300 on the CPU alone.
Jerry