Don't they have 2 connectors each? A total of 8? I don't think there is a affordable PSU with 8 PCIe-power connectors.

I am extremely satisfied with the Sharkoon Rush Power series: they have 4 connectors, so with 2 (500W version for enough power on 12V rails) of them you will have no problem powering your rig. http://www.sharkoon.com/?q=en/content/rush-power-m