As for converting to USD, that just creates problems as some careless readers (me sometimes) will think of US prices and get confused. The price when converted doesn't give any extra info that the price in NOK doesn't also provide, and it's potentially misleading. Also, doing the conversion means that somebody will have to convert back in order to compare to prices of products actually available. I guess it's not as much an issue if you're only looking at those three power supplies, but likely a better pick is something else altogether anyway.
Anyway, the wattage is way more than you need. The current revision of XFX Pro/Black 850W uses Seasonic KM3 (which is borderline platinum on the gold-rated models) and has two EPS12V connectors. Those should be plenty, and they're cheaper than you were looking at before and definitely better than the Silent Pro Hybrid and newer than the Black Edition 1250W.
edit: if you really get mild OCs on the 8439s and want even more capacity for those or even the 6174s, Cooler Master V1000 is mostly the same thing with a better fan and higher capacity.
Edited by mikeaj - 3/2/14 at 12:00pm