What will you be doing with this machine? What resolution is the monitor? If it's for your parents, who like playing Zynga's games, a HD5550 would be more than enough.
Edit: Oh, and with the Antec case, there are often good deals on Antec PSUs. And, whether Corsair or Antec, you'd only need 500W for this build (unless you anticipate running two cards in Crossfire (ATi) or SLI (nVidia).
*make an IMAGE after you Activate Windows. OEM versions of Windows can only be reinstalled so many times (three?). However, if you create an Image after Activating you can RESTORE that instead of reinstalling.