DO IT!
You can still build a WC system that beats air cooling. You can take the q6600 to 4 GHz on water
I thought about water cooling my CPU and even started to but I know a friend that was selling off the phase change coolers he built (cheap but I'm not sure why) and I am going to get a unit for $350 - $500 pretty soon if things go right. I still plan to water cool my video card and north bridge though. But I still will probably WC some of my other rigs. Let me know if your interested in a cheap single stage too because the guy I know has a couple
And he will tune them to your heat load. They start at $450 (I got the friend discount
)
But yeah, definitely do it!