It all looks ok, you don't really need a sound card unless you are a music junkie or plan to have high definition surround sound speakers, at least that's what I understand, and here's a hard drive that's $79 after a 50 dollar rebate http://www.tigerdirect.com/applicati...sku=THD-250A2,
I know it's not much cheaper, do you live in america? because you can check out www.tigerdirect.com
and they always have good deals on computer parts. It's where I got my set up from.
Edit: You might can downgrade the PSU to about a 500W, I'm not sure though.