I've played with liquid cooled systems quite a bit. If you're looking for performance gains, it gets a bit involved. But if you're looking for a quiter option than the normal CPU cooler, it's the way to go. You can buy an entire setup now for about $150.
A few pieces of advice though...
1. Get a system that includes everything (unless you're real keen on fabrication). Or at the very least, try to get all the parts from 1 company. That way you know everything will work together.
2. Don't buy a system with a tiny radiator. The smaller the radiator, the smaller the fan. Smaller fans have to spin faster to move the same amount of heat. It defeats the whole purpose (noise).
3. Not all cooling blocks (the part that mounts to the CPU) are created equal. Read the reviews before you buy.
4. Don't worry about liquid cooling anything else except the CPU. If your northbrigde has a fan, you can liquid cool that also, but it's usually not necessary. Forget about RAM cooling, it's useless. Video cards can be overclocked if cooled properly, but overclocking is generally not a good idea for DAWs.
5. When you move the CPU heat outside the case (with the radiator) you are also doing away with the need for a lot of other fans, since the case temperature drops dramatically. This is perhaps one of the biggest advantages of liquid cooling. Feel free to experiment with lowering case fan speeds to reduce noise.
6. While you are setting it all up, run a monitoring program to keep an eye on the temps. Then run something that will put the CPU under load to make sure the system can stay cool over prolonged periods of time (see #3).
Do a web search on liquid cooling before you make any decisions, there's plenty of information out there. Keep in mind that there are 2 basic liquid cooling setups; Active and passive. Active means that there's a refrigerant involved that actually makes the CPU colder than room temperature. These systems are more expensive and more complicated than their passive counterparts. Active systems are where you will see performance gains (as long as you are privy to overclocking techniques). Passive systems never get colder than the temperature of the surrounding air. This is still cooler than a standard CPU fan, so stability usually increases even if you're not overclocking. Passive systems are cheap and simple. If it's your first time playing with water inside your computer, it's definatly the way to go.
Either way you go, passive or active, you will certainly see a decrease in noise, and you'll probably see an increase in stability. I wouldn't recommend overclocking a DAW though (which is the reason for liquid cooling most of the time), there are almost always stability issues.