Budget Gaming (how original)

I've been lurking here for a while, and I've finally saved up enough money to post. Here goes.

Approximate Purchase Date: Within 2 weeks


Budget Range: 700-800 USD Before Rebates


System Usage from Most to Least Important: basic multitasking (browsing, media, word processing, etc.), gaming, modeling (Autodesk Maya and Mudbox)


Parts Not Required: keyboard, mouse, monitor, speakers, OS


Preferred Website(s) for Parts: newegg


Country of Origin: USA


Parts Preferences: I'd probably prefer Intel to AMD, but anything solid will work.


Overclocking: Maybe


SLI or Crossfire: No


Monitor Resolution: I will be using a 1080p TV as a monitor, and I will also need an RBG cable(?) to connect it.


Additional Comments: I want something that will be upgradeable after the initial build, so take that into consideration. And as far as gaming goes, I don't care if I can play Crysis on max or whatever the benchmark is, but I do want games to run smoothly with normal settings, including Diablo III when it launches. Take your best guess for DIII requirements...