How about just adding a couple of these splitters to the single PCI-e cables that come with the suggested EVGA power supply.  Problem solved and they are less than $4.

http://www.amazon.com/JacobsParts-Express-Power-Splitter-Cable/dp/B00JLU0UQ4/ref=sr_1_3?ie=UTF8&qid=1443718016&sr=8-3&keywords=pcie+splitter