Hello !
Just a suggestion:
Would you feel more comfortable with having a second power supply dedicated just for the amps.
WOW, Up to *70A* You'll have to increase the wire size (lower gauge) to pull the amperage through a single physical wire.
Here's a couple formulas that may help:
Amps = Watts / Volts
Amps x Volts = Watts
Even thourgh the NZXT Hale90 PSU says +12vdc @ 70A, that's at absolute max output before the fire.

To make the PSU last a long time. I'd calculate a comfortable 80% PSU output. now is only 12+vdc @ 56A
56A x 12vdc = 672 watts
The total RMS output of all amps & subwoofer combined shouldn't exceed 672 watts or the power supply will have a short lifespan.
Disclaimer: I have been wrong before..

Keep the pics coming...
Can't wait to see the cabinet...
www.cavicchiojukebox.com