A very promising cooler that has not been released yet is this - http://www.geek.com/chips/zalman-launches-worlds-first-cpu-liquid-cooler-using-nanofluids-1567407/
However the H100i will perform well for overclocking. The PSU if it is a good quality brand (like seasonic or XFX) will suffice. I don't think I would overclock to 5.0Ghz instantly I would do it in increments, however if you know what you are doing then.....