For a PSU I'd recommend getting a server one (94%eff. Platinum rated). ParallelMiner sells some really nice kits. 
But you need to do some modification on the server PSU.
PICO adapter for MOBO and everything is a OK
(also, risers with 6-pin pcie for straight connection from PSU)!http://www.parallelminer.com/product-category/power-supply-kit/