> I had big problems with the Zalman 400W PSU unit. Not really a
I don't think that's the fault of the power supply - it's designed to
cool itself, not necessarily the entire box. Running a hot system
like yours, you probably need a least one case fan. Try two low noise
120mm fans with speed controllers on them - one at the front of the
case, one at the back near the CPU.
Personally, I've found the Zalmann 400W to be really well made and
quiet. The weight alone gives you an idea of the quality - which of
course has to be paid for.