Hiper have excellent PSUs. There have been reports of the 580W having trouble at absolute maximum load, but not many PCs stress a PSU to its absolute limit. I personally have never had a burp out of my 480W TypeR, it has steady rails and quiet operation. I will be getting another 6800GS for SLi at the end of the month, it remains to be seen if it can handle that. I have no SLi connectors so I'll be using 4 molexes
I'm going to buy a 600W SeaSonic S12 in the near future too, and they are about the best PSU you can buy apart from possibly PC Power and Cooling. I don't like Enermax as a brand, Antec have a couple of good PSUs and so do Fortron.
For referance, there are not many manufacturers
of PSUs, most (OCZ, Antec etc..) are re-branded. Fortron, SeaSonic, PCP&C and Zippy make their own PSUs, and I'd tend to stick with the actual makers not just people who slap a sticker on another unit.