Something that I love and cherish of its superb cooling, and if you are overclocking (which you are,) get four 120mm fans and attach them to the radiator (two on top and two on bottom.) Make sure to make it a Push-Pull if you want (pull from the bottom and push from the top.) It is really nice.
Corsair H-series coolers aren't true watercooling; they are a form of stand alone liquid cooling that is based on how actual watercooling functions, just not to the performance of user-serviceable functionality.
For $200, you can build an excellent CPU-only watercooling loop...for $130-$185 you can simply buy an XSPC Rasa watercooling kit that will outperform that H100 with everything included, except water.
H2O cooling is pretty much a "hobby" for those who like to tinker with their PC daily. The Corsair H2O stuff is very inefficient and over-priced compared to quality air-cooled HSFs. Unless you're doing H2O as a hobby you'd be better off with good air cooling IMO. real water-cooling systems start at ~ $200 and go up.
The link below shows you objective cooling test data for many HSFs and some H2O coolers. Also keep in mind that H2O coolers do experience water leaks which can damage the rest of your PC hardware. See the Corsair H2O forums for tales of woe.