Don't know what the pricing is on Win8 Pro, but if they are comparable, go with Win8, even if you don't plan on using. You get downgrade rights with Win8, so you can still legally use Win7 Pro, but you've always got a Win8 license if you decide to use it instead.
What do you mean downgrade rights? Anyways i plan on skipping w8 totally. This rig will run w7 + mountain lion.
Do you really think gskill can test over a 100 boards just to make sure it works with ever single one and for asus to do the same?
If you go to the asus website and download the pdf for the board the ram i picked isnt supported. Plus it appears to be an older board from the one i chose. But thanks.