For a psu go with trusted makers such as corsair, antec, seasonic, xfx. You can also go with efficiencies (ability to maintain it's rated power) of 80, 80bronze, 80silver, 80 gold. There are modular PSUs which make cable management easier. Finally, you want to look at the amperage on the 12V rail(s). I prefer a psu to have a single high amperage rail with a decent efficiency and modular. Therefore, I usually go for a corsair. Modular is far more expensive though.