Corsair CMPSU-620HX 620 Watt Power Supply
It seems really tight with a high power correction factor, and rock steady voltage regulation, if this review is accurate. Hmmmm, a little too good to be true. The fan is punching out 39 db (more like 42 at full load, maybe), and with modular connections at the PS it's possible to have a failure.
http://www.bjorn3d.com/read.php?cID=945 This review shows more V fluctuation on power rails, and specs the V ripple too. This seems like a more realistic review. It has a 5 year warranty, and is selling for about a $160. It's a very good PS and just might be my next PS.
http://www.pcper.com/article.php?aid=279