Cool GTX
Nice build 
The case does not look big enough for (3) 480 radiators, looking forward to your updates as it goes under water.
Reminds me a little of my X99 Classified (3) Titan X(p) rig Nibbler ... more power
Better run a 20 Amp circuit or two 
It can hold one up top, one in front, and one in the bottom! I am going to go dual loop, 2 480's for the GPU's and a single 480 for the CPU. I remember the old x99 platform, I had 3x 780ti classified's back then. And in the same case as your build believe it or not! Mine was red and black however.
The idea for the breaker box is two 20Amp breakers on the same power phase running into the wall. I am unsure if it matters if they are on the same phase or not. The PSU's convert it all from AC to DC; but due to the delicacy of computer hardware I think its best to run both PSU's on a single phase. I am unsure how much power fully uncapped titan Xp's can suck, but I think 2 1600w T2's should be enough.
Here is some of what I have now in terms of water cooling parts (currently waiting on the 4th Titan waterblock in the mail):
In the graph above ^ lets call the red line "phase a" and the black line "phase b". The graph is a representation of AC frequency. In single phase power (residential) here in the states "phase a" is 180 degrees apart from "phase b". If one PSU was on "phase A" and the other on "phase b" im not sure if it would have any adverse affects to the computer.