I have an intel i5 2500k currently OCed to 4.2Ghz which idles at 31 degrees C and at full load is around 70 degrees C with a hyper 212 air cooler. The temps are ok but the problem is the fan on the cpu cooler is SO LOUD. I want a very very quiet maybe silent system. I'm thinking about getting an h100i with noctua fans running in pull. I was going to build a custom water cooling kit but i'm a noob to water cooling and have never done it and don't want to ruin my parts!
If you're all about monitoring and controlling, I too would suggest an H80i or H100i. Both offer great performance and CorsairLink2 is very cool. You can set your fan speeds manually by RPMs to control the sound/performance ratio to your liking. However if the Noctua fans aren't 4 pin fans, there may be issues controlling the RPMs. You may want to just save a few bucks and not buy the expensive, ugly (although amazing performance) Noctua fans and just stick with the already pretty decent SP-120Ls that are included (which are 4 pin).
I picked up a H70 Core for $50 on Tiger direct not long ago, so I would advise you to look out for deals. If you don't care about price, I would grab an NZXT Kraken X60, its a 280mm, so make sure it would fit your case.