Need Advice on the system i'm building

Hi, Im building a new system and im kinda of out date with whats in the current market and wheather what i have chose is suitable.

Basically I would like to use windows 7 in future and at the meantime i will be using windows xp before i decide to upgrade, so currently i have listed what i have chosen can u suggest if this is suitable. or advice me would be great.

also currently im looking for a PSU can u recommend me one which i be able to use with his system?


Option 1 (Total Price - £630.00)
Intel Core 2 Quad Q9550, S775, Yorkfield Core, 2.83GHz, 1333MHz, 12MB Cache, 8.5x Ratio, 95W, Retail
Asus P5Q3, iP45, S 775, PCI-E 2.0 (x16), DDR3 1066/1333/1600/1800(OC), SATA II, SATA RAID, ATX
6GB (3x2GB) Corsair Dominator DDR3, PC3-12800 (1600), 240 Pin, Non-ECC Unbuffered, CAS 8, DHX, XMP
1GB Sapphire HD 4850, PCI-E 2.0(x16), 1986MHz GDDR3, GPU 625MHz, 800 Cores, 2x DL DVI-I/ HDTV, HDCP
1TB Western Digital WD1001FALS Caviar Black, SATA 3Gb/s, 7200rpm, 32MB Cache
PSU???

Option 2 (Total Price - £520.00)
Intel Core 2 Quad Q9550, S775, Yorkfield Core, 2.83GHz, 1333MHz, 12MB Cache, 8.5x Ratio, 95W, Retail
Asus P5QC, iP45, S 775, PCI-E 2.0 (x16), DDR2/DDR3 1066/1333/667/800, SATA II, SATA RAID, ATX
4GB (2x2GB) Corsair TwinX XMS3, DDR3 PC3-10666 (1333) 240 Pin, Non-ECC Unbuffered, CAS 9-9-9-24
512MB Sapphire HD 4850, PCI-E 2.0 (x16), 1986MHz GDDR3, GPU 625MHz, 800 Cores, VGA/ DL DVI-I/ HDMI
500 GB Western Digital WD5001AALS Caviar Black, SATA 3Gb/s, 7200rpm, 32MB Cache, 8.9 ms
PSU???

Option 3 (Total Price - £505.00)
Intel Core 2 Quad Q9550, S775, Yorkfield Core, 2.83GHz, 1333MHz, 12MB Cache, 8.5x Ratio, 95W, Retail
Asus P5QC, iP45, S 775, PCI-E 2.0 (x16), DDR2/DDR3 1066/1333/667/800, SATA II, SATA RAID, ATX
4GB (2x2GB) Corsair TwinX DDR2 XMS2, PC2-8500 (1066), 240Pin, Non-ECC Unbuffered, CAS 5-5-5-15, EPP
512MB Asus HD 4850, PCI-E 2.0 (x16), 1986 MHz GDDR3, GPU 625 MHz, 800 Cores, 2 x DL DVI-I/HDTV
500 GB Western Digital WD5000AADS Caviar Green, SATA 3Gb/s, IntelliPower, 32MB Cache, NCQ
PSU???

btw how is Asus motherboard with the new core 2 quad cpu is it recommended?

please advice, thanks!!!

nami