I would not get 2 GTX 690s unless you know what your doing. Many games cant even handle Quad SLI. Thats means you'll have 2-3 Gpus sitting there doing nothing. Diminishing returns at full force here.
I would suggest 2-way SLI GTX 780/780TIs
You only need an Extreme Edition Processor if your Using Programs that can actually use the Cores/Threads, Or if you really need 40 PCI-E Lanes.
Same for an X79 Board
unless your Video Editing Professionally then this seems like Complete Overkill. If your Gaming and doing simple Youtube stuffs (Maybe) then get
An Z87 Board
An Haswell i5 or i7
16GB RAM
The Video cards I mentioned Before
and a PSU to match the rest of your equipment.....
My personal Opinion since the OP didnt really say what this PC is being used for.
Im not even going to touch the PCI-E SSD =P