Overclocking the e6600: Liquid or Big Air?

Now that the retail Conroe chips are filtering out into the public, I have been planning a new system build. This will be my first overclocking rig, and I have been doing a lot of research into cooling. My question is this: Since the Conroe is a relatively cool-running processor in the first place, is it really worth the extra $100 or so to water-cool it?

These are the factors in consideration, from most important to least:
1. Overclocking Protential: How many more volts, and subsequently more mHz, will water cooling really give me?
2. Maintinence/Usability: How much time will I be spending bleeding or fixingmy water-cooling loop, instead of actually getting to use my computer? Which will be harder to move to the LAN party: A liquid system or a system with a GIANT heatsink?
3. Noise: Which will make more noise: An internally mounted 120mm fan on a monster heatsink, or two 120mm fans on an extrenally mounted heater core?

The specific cooling hardware I was looking at would be something like this:
Big Air: Tuniq Tower 120 (Whenever it becomes available)
Liquid: Swiftech Conroe-Compatible CPU Block, MCP655 Pump, and Single-Pass Double Heatercore