CPU - Definately want to get 90nm Winchester for that 3500+. And I got a 3500+ 90nm Winchester for 252 bucks from monarch, dunno where you're getting your prices.
PSU - For the PSU, get a better one!! Can't stress this enough. A good PSU makes a healthy computer.
HDD - Totally agreed, Seagate makes the best hard drives. And only one 160 - 200gb SATA drive is enough, you really don't need more than one hard drive.
Video Card - For gaming, you oughta up your graphics card to a 6800GT, which performs a little over twice as well as the 6600GT does.
RAM - Haven't heard much about Patriot memory. You'd probably want to stick with OCZ or Corsair or Crucial to be safe.
Motherboard - nForce4? Looks like at least 150 for a single GPU one, at least 200 for an SLI version. Better stick with nForce3, less buggy and NF4 really doesn't have a great advantage over the NF3 if you aren't going to use SLI.
-Me