First off, if you're not overclocking, the stock cooler for the cpu should be just fine, and the hard drive and chipset coolers are probably unecessary.
I'd recommend OCZ's SSDs. They are much faster.
24gb of RAM is a bit of an overkill. I'd get probably 12 to begin with and IF that isn't enough (which it will be) then get more...otherwise you're just wasting money.
That power supply is an overkill as well. Try a Corsair 850w
, or a Corsair 1000
if you don't want to go that low...
Why get 2 cheaper gpu's when you can buy 1 good one? You said it yourself that cooling is important. GTX 580
is your friend.
I never recommend getting more than a 1tb drive. I myself try to stay way from even 1tb because thats a lot of data to lose if the drive fails on you...that case has plenty of room for multilple drives anyway.
That leads me to the case, which is also an overkill. $660 for a case!? It's your opinion, but I wouldn't spend that much on a case...I'd get a cheaper one. The HAF X case
is big enough, with great cooling, and its only $200.
And Sandy Bridge > Nephalem, Gulftown