go for a psu with a top and one back fan as opposed to one with 2 80mm fans on the front and back these style psu will not fit with the top fan i recently used one of these in a build and used this psu
actually just the 400 watt version but w/e
i also modded it and swapped the included clear boring fans for blue led ones
actually the blue led fans included in the case and then i purchased all matching blue led ones for the case.
the psu looks great and is a very good psu for the money
unfortunately i opted to go the way of a 450watt super flower modular psu with 14cm fan
i use aspire's x-infinity case and suffer from the same problem of fitting the top fan in the case. my solution was
heres my case to give you an idea of it