[airspirit]

Unless you are considering phase change cooling which is by and large big, ugly, and dangerous to the uninitiated (arr, me bones'r meltin' arr ... ), look up direct peltier cooling. This can be reasonably affordable if added to a preexisting watercooling kit. Otherwise, consider going with a prometia system. At $450 at some places, it is perfectly acceptable considering that creating a good watercooling system with pelts will run you upwards of $250 if you go cheap and used. For the performance difference it is worth it.

As for adding a pelt, you just need to consider whether your system can handle the extra heat load, make sure you have a capable independent power supply, and a block that can be rigged to hold one ... plus the insulation and such involved.

Using a chiller involves some insulation if you are going more than a few degs under ambient, a costly part (a good dehumidifier or such that will work costs upwards of $100 typically), and a good deal of modification to make it work.

Ask yourself these q's before you get started: what are your goals, how much are you willing to spend, and how many risks are you willing to take? Once you've answered those, study your options, narrow them down, and study some more. Don't undertake a project until you are confident that you can handle anything thrown at you, or in these circumstances you are setting yourself up for disaster.