Liquid Cooling System?

Well im looking into buying a liquid cooling system to cool both my CPU and GPU at the same time. Im not familiar with this at all so im looking for some opinions.

Thanks
Peter S.
Universe-Gaming.com President

http://www.tomshardware.com/howto/20040630/index.html
has a few, so you can see what sort of $$$ you are looking at. There are cheaper kits available, but they don't cool as well, your gains are more in being quiet. You can also make your own system, since all the parts are available separately.

Well, I was also wondering what other liquids you could use besides water to keep the system cool, im asking this because the temparature in my room is extreme. this is the reason im looking into on of these systems.

EDIT: Well i actually mean what coolants can i add to the water to make it cooler.

Additives don't make water "cooler". People add things to water to make it less corrosive, decrease surface tension, prevent microbial growth, and lower the freezing point/raise the boiling point. Of these, decreasing surface tension can increase heat transfer and more efficiently cool the cpu.
Lowering the freezing point is only needed when active cooling (peltier, refridgeration) is used. Most water cooling kits are passive, so there isn't an issue of being "too cold".
If you are operating in a very high temperature environment, these passive coolers won't cut it, you'll have to look at peltier cooling, or a vapochill (big $$$).