I totally disagree about overclocking vs. noise. A louder system will allow you to push closer to max OC, but a decent build will allow both.
My system runs stable with a 35% CPU OC, and cooling is not why it won't go faster. Both fans and the pump are undervolted, and the HDs are in Smart Drives, so the PC is pretty darned quiet. This is just one example to show that it
can be done.