[Eronus]

The best I could do would be way over your budget, especially for modeling and rendering. Here are some suggestions though.

Vid Card: Newegg.com - SAPPHIRE Vapor-X Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Desktop Graphics / Video Cards

CPU: Newegg.com - AMD Phenom II X4 940 Deneb 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM2+ 125W Quad-Core Black Edition Processor - Processors - Desktops

Mobo: Newegg.com - GIGABYTE GA-MA790X-UD4P AM3/AM2+/AM2 AMD 790X ATX AMD Motherboard - AMD Motherboards

Memory, This is the most important part I believe because rendering is very memory intensive and as of recent, prices for memory sticks have gone up a good amount so here's just a single set of 4gb(2x2gb) memory which is good, but I would personally prefer 6gb's for rendering 3d models.

Newegg.com - G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBPQ - Desktop Memory

Hope this helps.