Even if EVGA offer their SR3, you need a new case, probably power supply, two processors, heatsinks, the board itself, enough memory for it etc. I reckon an SR3 board with ram, heatsinks and processors will run up about £2200+. Whereas even the most expensive X79 will be £330 + whatever for the chip, which will be unlocked and able to clock much better.
I can say that the board looks magnificent, although changing the backplate practically made me **** my britches...take off the cpu cover then remove it, then turn over the board for the backplate. Eeeep.