I dont think jumping straight to watercooling for a beginner overclocker is a good idea. Its always best to learn on a more "stable" platform with a high end air cooler first. Once you've extracted what you can from air cooling, then investing in a custom water loop makes sense.
Jumping straight to water would probably end up costing much more for sub-par parts for a novice.
Hell, I still do the majority of my overclocking with beefy air coolers - nothing beats the convenience.