If that PSU was having issues, it's a lemon. I think Phil was running on 120V back then too. 240V is easier on the PSUs, I hope you'll be using 240V with 6 S7s?

EVGA says you can pull 1300W DC from them, IE ~1450W at the wall for 10 years. That's good enough for me! Worse case they replace the PSU for free.