Do you have an app that needs quad channel ram at that data rate? Last thing I saw was that it's irrelevant in real world gaming, surfing, and general use. As for the speed, since you have to loosen timings to get the higher clocks, it's a zero sum game. Intel chips only officially support up to 1600MHz RAM anyway.
The 3820 is a locked processor and wouldn't need anything more than the stock fan that comes with it. The CPU is also PCI2.0 so wouldn't make max use of the PCI3.0 on the mobo (IB will).
Power supply is way overkill even if you went tri-SLI with an overclocked CPU (need 1KW max to have a 20% buffer).
Do you need the extras the more expensive boards provide? A simple ASRock board will save a ton of money, support 2-card SLI/CF, and provide all the basic interfaces. It looks nice even, but you can't see inside the C70 anyway.