If you're referring to the coolers, the H100i is a more powerful water cooling unit than the standard fan cooler that comes boxed with the processor. For non-overclocked systems the stock cooler is fine in the majority of cases.
I also agree that the guy saying not to try and build your own and that it's cheaper to buy pre-built is wrong. Research the process, research your part list (like you're doing here) and take your time building it and you're good to go.
...we were on a break