Hey Philipma, I seem to find you around the forum a lot, and it looks like you're very knowledgeable. Now, you say I can run 6 GPUs with 1600w, does that mean I can run 5 Fury GPUs with an Evga 1300w PSU safely?, again, I don't plan to do nothing crazy with them and with probably undervolt and the price difference between 1600w-1300w is important.
You would be fine, especially if you undervolt.
I'm running 4x 290 @900/1250/-56mV on a 850w PSU, entire rig is drawing pretty much exactly 850w DC.