Just a couple comments. 1200W is WAY overkill - even for that card. A good 750W would be just fine, 850W at most is all you need, unless you will be running with two cards - which, IMO, would be a waste since the 6990 is excellent as it is.
Virtually all motherboards come with decent integrated sound these days, and the better boards come with excellent sound.
I don't see an operating system listed. Understand only the "boxed" full Retail license can be transferred to a new computer (or upgraded motherboard). It is illegal to use an OEM license that came with or was purchased for another computer on a new computer. If the disk is “branded” with a computer maker’s brand name, or says OEM/System Builder, Upgrade, Academic Edition, or "For Distribution with a new PC only", then it is not transferable to a new PC (or upgraded motherboard) under any circumstances. These OEM licenses are inextricably tied to the "original equipment". If that is the case, I recommend 64-bit Windows 7 or one of the many free Linux alternatives. Just ensure it is 64-bit since you have selected 8Gb of RAM.
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