£1200 build advice on motherboard and gpu

APPROXIMATE PURCHASE DATE: Within two months.

BUDGET RANGE: £1200

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: gaming, surfing the internet, listening to music, watching movies,

PARTS NOT REQUIRED: keyboard, mouse, monitor, speakers, OS

PREFERRED WEBSITE(S) FOR PARTS: Ebuyer, scan.co.uk but I am open to ideas

PARTS PREFERENCES:


Case

Coolermaster Cosmos S
http://www.ebuyer.com/product/142276

Or

Antec 1200
http://www.ebuyer.com/product/143852


PSU

Coolermaster 900W UCP (Ultimate Circuit Protection) PSU - 80% Silver Certified Efficiency
http://www.ebuyer.com/product/147987


Motherboard

Asus P6T Se ix58
http://www.ebuyer.com/product/161061


Processor

Intel I7 920 2.66ghz
http://www.ebuyer.com/product/161171


CPU cooler

Noctua NH-U12P SE1366 CPU Cooler
http://www.ebuyer.com/product/165572


Graphics card

BFG GTX 275 OCX 896MB DDR3 X2 in SLI
http://www.ebuyer.com/product/168745


Memory

Corsair 6gb (3 x 2gb) 1600mhz XMS3 dominator
http://www.ebuyer.com/product/152641



OVERCLOCKING: Yes

SLI OR CROSSFIRE: Yes

MONITOR RESOLUTION: 1920x1080 (monitor used is a 23'' Dell S2309W)

ADDITIONAL COMMENTS:

I am really just looking for guidance from all you lovely, knowledgable people! I am open to suggestions.

I'm not concrete on anything but I am particularly unsure about the motherboard - can't seem to see any clear winner in the reasonably priced boards availible.

Anyway folks, let me know!

Thanks,

SS