New System build Advice please

Hi guys this my first post in the forum

I have a system about 6 years ago final i made my mind to get a new one build

I need some advice from you this what i have put together I am planing to spend around £1000 max for just the Box.

I think is a good amount to spend.

I am planing to use it mainly for 3d work and rendering scenes and sometime games. I was thinking SLI but i dont think I will get any more power if a get 2 low end card. Is better to go with a single good one and get a second one in the future when prices drop.

The system will run on Win XP PRO x 64bit

I am think about overclocking but is something that I have not done before. I know that Q6600 can be overclocked well.

Here is what I am thinking

2 x Western Digital Caviar SE16 500GB SATA2 16MB 7200RPM (RAID 0)

Antec Nine Hundred black miditower, Side panel window

Asus P5N32-E SLI, nForce-680i SLI, ATX, Socket-775, 2xGbLAN, DDR2, 2xPCI-Ex16

ASUS Silent Knight CPU Cooler, Blue Light, Socket 478/775/939/940/AM

Intel Core 2 Quad Q6600 2.4GHz Socket LGA775

LG DVD±RW burner, GSA-H62NRB, SATA, Dual, Black and White

OCZ Platinum DDR2 PC6400 4096MB KIT, w/two 2048MB PC6400 XTC, CL5-5-5-4

Thermaltake Toughpower 850W, Modular, 8xSATA, ATX/EPS, 4xPCI-E, 20/24pin

XFX GeForce 8800GTS 560M 320MB XT GDDR3, PCI-Express,2xDVI/HDTV/HDCP,560/1700Mhz

Any advice welcome I am open to suggestion.

Many Thanks

Chris

what size are you thinking?

well I am planning to make the system sli ready and get a second card as soon as prices drop. Well I looked for a 8800GT

XFX GeForce 8800GT 640M 512MB XT GDDR3, PCI-Express 2.0, 2xDVI/HDCP, 640/1900Mhz which only £10 difference