The Coolit Eco is not he worlds best water cooling system. See:http://www.frostytech.com/articleview.c ... 662&page=5
Why don't you try replacing the two noctuas on the radiator with two Scythe Gentle Typhoons. They are good static pressure performers. That means they will push more air through the radiator at lower RPM.
If it is just the CPU that is generating much of the heat and the rest of your components do not have a heating problem, try reversing your air flow so that the radiator is being cooled with cool incoming air as opposed to hot outgoing air.
As a last resort you might consider changing your CPU cooling system to a high end Corsair water cooling system... or even a large aircooler like the Noctua NH-D14.
What is the source of your noise? Maybe changing all your case fans to undervolted Nexus reference fans might help?
I would start by getting a single 1150 RPM Scythe GT fan and a single Nexus reference fan and experimenting. See what a single 1150 RPM Scythe GT fan mounted inside your case on your radiator does. That by itself might make a big difference.