I have some suggestions:
A very good top end build.
1. Do not try to use a SSD in raid-0. You will do nicely in synthetic benchmarks, but not in actual usage. I know, I tried it.
Instead, of a single 120gb ssd, buy a 240gb ssd. Space management will be better, and larger drives tend to be a bit faster. They have more nand chips that can be accessed in parallel. Sort of an internal raid-0.
2. Consider buying a GTX690 up front. It has 2 GTX680 gpu's under the cover. A single card will run cooler and quieter. It will only need a 650W psu to run.
Yes, it is a bit more expensive than sli GTX680, and might benchmark a bit slower, but the other factors are very attractive. Do some research on it.
3. Buy a aftermarket cpu cooler. A tower type cooler with a slow turning 120-140mm fan will keep your cpu cooler and quieter.
A cm hyper 212 will do the job, or a more expensive Noctua NH-D14 or phanteks will be as good as it gets.
4. Reminder... to access >16gb, you will need windows 7 pro or ultimate.
5. Your case is fine, no added fans are needed. They are easy to add later.
6. Ivy bridge and sandy bridge cpu's do not benefit from fast ram. DDR3 1600 is plenty.
Read this on ram speed scaling: http://www.anandtech.com/show/4503/sandy-bridge-memory-...
1.5v ram does not need fancy heat spreaders which are mostly marketing. Buy low profile ram so it will not interfere with your cpu cooler.
7. Take the time now to download and read, cover to cover, the case and motherboard manuals. You will learn much.
PSU is fine. 850W is more than enough for two high end cards. If you're gaming at 5760x1080, a single 680 won't perform much. You'll need to get at least another card if you want to game at high details.
Since I came back I have finished built my system. I went with these components:
CPU: i7 3930k
GPU: EVGA GTX 680 4GB classified
Mobo: Rampage IV Extreme
CPU cooler: Corsair H100i (Push/pull with Noctua NF-F12 PWN)
RAM: Corsair Dominator 32GB 1600MHz C10 DDR3
SSDs: 2x Crucial M4 in RAID0
HDDs: 4x Western Digital Caviar Green in RAID10
Case: NZXT Switch 810
PSU: Corsair AX850
Here are some pictures:
I have achieved stable overclock at 4.5GHz on the CPU and 1250MHz on the GPU.