Guess it's off to Fry's to buy a couple 6-pin PCIe extenders and butcher those instead ?

 Are we going to need 2 6-pin PCIe's plugs butchered, or 4 x 6-pin PCIe's plugs to power both sides ? Each board needs to be powered or only one ?

 Can we combine 2 x 4-pin molex plugs to drive these ?