Based on that it's peak wattage can go over to 500W w/ the small fan, I think it will be fine with 380WMy system should consume around 380W under load, close to the 400W.
Little worried about the life expectancy if run passively.
I'd like to know if the case of the HDPLEX AC-DC really acts as a heatsink, hence would benefit from watercooling.