Upgrades *please move*

Currently I have a computer with the specs listed in my sig. It has worked faithfully for me for a while now, with me only having to add more RAM and a better video card. However, I'm looking to do a major overhaul on my PC during this upcoming Christmas holiday when I recieve some money from relatives wishing me luck and the bonus from my summer job.

The first upgrade that I was looking at was a new motherboard/CPU combo. I would like to get a new SLI motherboard and an AMD processor with a Venice core for overclocking. The 6600GT that I currently own is unfortunately AGP, but I want to get a PCI-E card so that I can put it in my new mobo and be set for the future. The second upgrade would have to be a new card. I was thinking possibly a 6800GT. Whatever card I do wind up getting, it will have to be PCI-E. Below is a tentative upgrades list. Let me know what you think.

MSI K8N Neo4 Motherboard -- $124.00
AMD Athlon 64 3200+ Venice CPU -- $190.00
XFX GeForce 6800GT -- $289.00

Total: $603.00 USD

I might be in the minority on this one, but if I were you, I'd skip right past the 6800s and score a 78.

I know they're more expensive, but it will last you longer.

That's my 2 cents.

Oh, and make sure your PSU is powerful enough to handle that load. Every Venice based system my friends have built, they've made the mistake of having a weak/cheap PSU.

Good luck.