Help Building Budget Gamer

I am looking to build my first PC, i think this would be doable by me because i have a fair amount of knowledge into computers.

I want a computer with an HDMI out and hopefully 5.1 surround sound capabilities.

I want a computer that can run World of Warcraft nicely, and maybe a few select other games (nothing too graphics intensive.)

I would also like a hard drive on the larger side, pushing around 1TB as i do a lot of video/music downloading.

I am only 17 and working a part time job so my budget is going to be around 600 or so bucks (the cheaper the better!!!)

What i don't need: monitor, keyboard, mouse
What i would LIKE, but DON'T NEED: cool looking case with you know the lights and the cool see through window

So are my guidelines possible to reach on my budget?