Have you looked into Vapochill
Vapochill is weaksauce, mach makes a good kit and OCZ may release a phase change kit soon too. DIY phase change is still king tho.
The only thing you have to worry about is condensation, as with any water cooled system.
Not with watercooling, you need to get below ambient temp to get condensation, And with enough foam and grease it's no problem.