eVGA 750i is the only decent MB I can think of that can support two 8800GTX cards and a Core 2 Duo at the same time. I'm assuming you do want two cards, otherwise the 850W PSU and the Tempest are way overkill.
If you don't intend to add a second video card, something like GA-EP45-UD3R would be good and it's cheaper.
I'd have to agree with aevm. That Gigabyte board is sweet. One thing to think about though, for about $15 more, you could get GIGABYTE GA-EP45C-UD3R, which supports DDR3. The price on DDR3 has come down a bit....I'd definitly dump the vista basic. Vista premium or ultimate is much more polished, XP pro is alot more polished.
I'd dump the Vista Basic too, and get Vista Home Premium 64-bit instead.
XP Pro has some advantages, absolutely. Of course it's more polished, after 7 years and three months of free beta-testing provided by 100 million people. However, it doesn't have DirectX 10, and you'd want that in a gaming box.
Also, XP-Pro 32-bit will see very little RAM (2.75 GB, I think, with two video cards, and 3.25 with one). There's an XP Pro 64-bit too, but it's not designed for gaming and it has some compatibility issues.
Funny thing, I have a board with DDR2/DDR3 support myself (GA-P35C-DS3R). These boards look good on paper, but they have some disadvantages. They tend to overclock less well than their DDR2-only versions (GA-P35-DS3R, GA-EP45-DS3R, GA-EP45-UD3R, etc.). They also cost a bit more, usually. Finally, they need you to take out the DDR2 before you can add DDR3. They'd be a lot more tempting if they could use the old DDR2 and the new DDR3 together, but they can't.
I see what you mean, Im on a buget so only got around £600 to spend on components as already got screen, mouse and keyboard.
I read that vista basic is better for gaming as the other versions install loads of other applacations to your system that slow down your performance, if its only a system for gaming and not media/surfing ect then basic is better ?
Also read that 32 bit version is better as 64 bit version has loads of hardware driver issues and only a handfull of games run well on the 64 bit version.
Now im really confused as i ve got conflicting suggestions?
All i know is that i dont know enough about pcs and components to decide, nightmare !!!!!!!!!!!!!
With the 32-bit version you'll see 3.25 GB of RAM. With the 64-bit you'd see the whole 4 GB. If you buy 4 GB more later, the 32-bit version will still see only 3.25, while the 64-bit would see 8 GB.
What you read about 32-bit/64-bit, was that about Vista or about XP? It is perfectly true for XP. For Vista however not so much, AFAIK. A device or program that wants a Vista certification must pass the same tests on 32-bit and 64-bit first.