Water cooling isn't magic. Depending on the set up you use, you will run 5 to 20 degrees over ambient. The closer to ambient temperature the water gets, the less efficient the radiator becomes at exchanging heat, so as room tempture goes up, the systems ability to remove heat goes down. Short version is that a water cooled computer in a hot room will run hot. What water cooling can do is move a hell of a lot more heat than an HSF. Good thing for intel cpu's.
With all that said, how much do you have to spend?