Here are some things that I found that are cheaper than at newegg and are either better or the same, for less or just a tad bit more for the better parts. Keep in mind this is after rebates. Also you are going to need at least a 600watt power. Another thing is you will need a HD around 320GB should be more than enough but recommended.

AMD 6400+ Black Edition 3.2Ghz$169.99
EVGA GeForce 8600GT 256MB$74.99
CoolMax 600W SLI & Crossfire Certified ATX Power Supply$56.99
Coolermaster Case$82.99 The one you chose was flimsy this one is less flashy and sturdy. Also it allows for some major cooling.
Samsung Lightscribe 20x Optical Drive$31.99
OCZ Reaper 2GB RAM (2x1GB) 800 $39.99
COOLER MASTER GeminII RR Heatsink *VERY IMPORTANT*$0.00
Western Digital Caviar SE 400GB$71.50
MSI K9N4 SLI-F Motherboard - NVIDIA$89.99 Better than the one you had on your list.

Total $619 after rounding up to the closest dollar. This is a hell of alot more for a hell of alot less and its including the HD. Remember that this is including the rebates so you will need to save around $700 to pay before the rebates (mail in only).