New Build, what do you think??

[Ares202]

Ok so im going to build a new PC this month and i want to know what you think about my choices of hardware, any suggestions and reccomendations are appreciated

OS: Windows XP 64 bit edition (i can get this free from university)

CASE: ThermalTake Kandalf VA9003BWS Black super tower +Window c/w 25cm fan

Motherboard: Asus P5N-E SLI NF650i SLi, S 775, PCI-E (x16), DDR2 533/667/800, SATA II, SATA RAID, ATX

PSU: OCZ 600SXS StealthXStream 600W PSU
3.3v 36A,
5V 30A
12V1 18A, 12V2 18A, 12V3 18A, 12V4 18A
-12V 0.5A

CPU: Quad Core Q6600 SLACR 95W and Arctic Cooling Freezer 7 Pro bundle

RAM: 2x OCZ 2GB Kit (2x1024) Special Operation Edition DDR2 PC2-6400 800MHz 5-5-5-12
OCZ 2GB Kit (2x1024) Special Operation Edition DDR2 PC2-6400 800MHz 5-5-5-12 Dual Channel Memory Spec Ops Camouflage Heatspreader -
OR
OCZ 2x 2GB Kit (2x1024) Platinum Series DDR2 PC6400 800MHz 4-4-4-15 (which is better?)
2GB Kit (2x1024) Platinum Series DDR2 PC6400 800MHz Dual Channel Memory Rev. 2 With Platinum Heatspreader - OCZ2P800R22GK

Hardrive: 320 Gb Seagate ST3320620AS Barracuda 7200.10, SATA300, 7200 rpm, 16MB Cache, 8.5 MS

Graphics Card: 8800GT, not decided on which website to buy from yet

DVD-RW: Samsung SH-S202N/BEBN 20x DVD±R, 16xDVD±DL, DVD+RW x8/-RW x6, PATA,Lightscribe, Black, OEM inc. Nero

Sound Card: Im not sure on this one, i could use my old Audigy 2zs or go X-FI, what do you think?

Also i have a few questions
will i be able to get the Q6600 to 3GHZ with that cooler?
Do i need 4GB of RAM for windows XP?
Is that powersupply enough for a future upgrade to SLI?