Need help making a decision...

[Evil-Dragon]

Hi guys, please excuse my absence to the forums, i have been a bit busy as of late. I finally got a job and now have some money that i want to use to build a new PC. However, after 2 years of not building any machines i need some help and advice and possibly some recommendations on the following specification:

Case: Lian Li A70B Black Aluminium (http://www.kustompcs.co.uk/acatalog/info_1077.html)
Processor: Intel Quad Core Q6600 (worth getting a Q6700?)
CPU Cooler: Zalman CNPS9700-NT nVidia Tritium
Memory: Corsair Memory TWIN2X2048-8500C5D (x2 = 4GB)
GFX: Asustek GeForce 8800GTX 768MB or BFG GeForce 8800 GTX OC
Motherboard: Asustek Maximus Formula
PSU: Coolermaster 850W Real Power
Main OS HDD's: Western Digital 150GB Raptors (x2 in RAID 0)
Operating System: Windows Vista x64 Home Premium
DVD Drive: Sony NEC Optiarc AD-7191S 20x DVD±RW SATA (just noticed my previous spec was a DVD-ROM!)

Total cost is about £1400-ish ($2760) and will be built by myself

Things i am not too sure about is using Vista 64bit edition, is it stable and compatible enough to run games on? Is it worth getting a Q6700 over a Q6600 or is it just not worth the extra £200? Since the X38 motherboards are Crossfire only is it worth getting the new nForce 780i mb's instead in case i wanted to have SLI?

Anything else that you can see that's wrong or needs changing?