I had one PSU keep popping off , and I only run 4 Ants on any of them.  Felt really hot - it was cooled at the time with 2x80mm fans.  Swapped those out for 3x60mm fans, configured to pull air out, instead of trying to force air through.  Been running like a rock ever since.

I've had extremely good luck with the 3x60mm fans configuration, and would recommend you try that.  If you want to render your fans useless later on, you can clip the connector end off of it and put the wires directly onto the breakout board terminals (as long as fans are 12v), instead of worrying about the headers off the board.  I can snap pics tomorrow if you want.