I've been doing some homework...let me share
For $27 you can get a Xigmatek HDT-1283 including its 120mm pwm fan. A cheaper and very good air cooling solution. And what I'm using.
On water...which I am going to build later this month, I have learned the following:
1. A lot will depend on radiator size and the fans you put on it. For a margin with the small OC'd cpu you probably will want a dual 120 radiator. The better radiators make a difference. This is a radiator test.
2. The Dtek Fuzion is probably the best cpu cooler out there. They also have nozzles to adjust the pressure drop. A look inside shows why it works:
3. The Laing DDC 3.2 pump, also sold as the Swiftech 355, with an XSPC top is the way to go. The reservoir top is apparently a bit better. XSPC also has some interesting single and dual bay pump/reservoirs. This is a pump test
, and looking at the results and top descriptions will show why the XSPC has the edge.
4. The Swiftech kits may be the cheapest overall solution. Two kits makes it simpler by mounting the pump on top of the CPU waterblock. If you go with the single 120 fan radiator (and you can always add two fans to it) you can mount the whole thing in the case with no mounting issues (radiator on case rear 120mm fan, pump on the CPU water block).
5. If you can significantly lower temps you can increase the strength of the electrical signals signficantly.
If I have something in error, please correct me.
What do I plan? Tentatively, triple fan Thermochill with 6 fans, XSPC reservoir pump, and Dtek fusion for an overvolted, overclocked Q6600. I am thinking about the dual bay pump reservoir instead of the pump with res. If it works, I may replace the Dtek fusion with a Wintsch Labs Arctic Web TCM waterblock.