I wouldn't suggest getting that case and PSU. Mostly because the PSU isn't specified, and probably unreliable. You don't want a bad PSU to fry all the new parts.
If your HDDs are Sata, you'll be able to salvage them and save at least $80. Also try to salvage the CD/DVD drive if possible.
Check out this build. http://www.tomshardware.com/reviews/gaming-pc-do-it-yourself-geforce-gtx-560,3216.html
Switch out the graphics card for something slightly cheaper and budget for an OS.