Newegg has the SeaSonic SS-660XP² power supply for $134 -34 code "EMCWWVR42" -20MIR.
This is an 80+ Platinum power supply with hybrid fan control (a toggle switch makes it work as a passive unit at low load) and modular cables. It is rated to provide 55 amperes on the +12 volt rail.
http://www.seasonicusa.com/Platinum_Series_XP2.htm
I have one of these PSUs in my gaming PC. It has worked very well.