[KarmaKiller]

Yeah, actually Kevin silverstone makes quite a lot of the popular PSU's that are out. They are normally rebadged to other brands. They are VERY good units. If you can stick with it, it wouldn't hurt anything.

As far as the parts already on hand.

Quote:

sata hard drive-I'd reuse
cd drives- obviously not gonna make a difference, I'd reuse it also
case (optional - not against replacing if there's a phenomenal case for a great deal)- I'm sure I could probably fit a new one in with your budget, so I guess your call
4 gb ddr400 (again optional)
2 pci-x evga geforce 7800 gtx (optional, but would rather stick with these for now unless again a great deal)
fx-57 socket 939 amd processor.
Now for the remaining 3, I'd honestly do away with them. Here's why.
1. A ~$100 CPU will literally triple the performance that FX-57can give. Not only that, but your limiting yourself a good bit by trying to find an already outdated motherboard. Plus the RAM is pretty outdated, but I know you know that already. Again, limiting your choices.
And the GPU's.... I use to have a 7800, and while it was a good card for it's day, again, a ~$100 GPU will match the performance, or beat the 2x 7800's in SLI. Not only that, but older SLI boards didn't scale near as well as the newer boards do.

Not only that, but really with your budget you could get a new CPU/RAM/Motherboard/Case/GPU combo easy, and still have money left over. Plus in a newer system, you won't have to worry about bottlenecks (which I'm almost certain the FX chip would even bottleneck the 7800's in SLI)

Plus I also believe to find a motherboard to fit all your current parts, your most likely looking at buying used goods. Which I guess it's nothing bad, but you could really build a modern kick ass gaming rig with what you have for a budget.

I'll make a list of all new parts, then I'll try to dig up a motherboard that'll work with the parts you have listed. Maybe I can find something on the cheap that will get you by if you don't wanna spend the doh now.

EDIT:
Forgot the most important thing, a new rig will get you mucho PPD.