It would work. I regularly use Seasonic X power supplies (2x 8pin and 24-pin) on dual-socket motherboards. But what exactly are you getting?
AMD Opteron 6234, a dual-socket motherboard like the H8DGi-F, and 8x4GB DDR3 ECC-Reg?
TBH, I'd rather get dual Xeon E5-2620, a dual socket 2011, and 8x4GB DDR3 ECC-Reg for basically the same price (2x$400 + $400 + RAM). Folding@Home and other distributed computing projects often rely on heavy FP computation and Bulldozer won't really give you any advantage as it's really only 12 FP cores. Abu-Dhabi/Piledriver (the Opteron 6300 series) will give you a little leg-up over Bulldozer because of it's second-gen optimizations in scheduling/etc.