go for water cooling
Pump: Rio 180, cheap, quiet, and very small = 12$
http://www.graystonecreations.com/acc.htm
Waterblock: The UnaBlock, it's only $15 here
http://becooling.safeshopper.com/6/117.htm?83
you'll need something in the water to prevent algae from growing, and prevent corrosion. Normally I'd recommend Water Wetter here $4
http://becooling.safeshopper.com/13/23.htm?53
You'll need a radiator. Go to an auto parts store, and ask for a Heater core for a 1988 Ford Escort with air conditioning. You might want to call around and find the best price, it should be under $20. I'll call it an even $20. They come with 5/8" fittings, you'll need to make adapters. Necessity is the mother of invention, I'm sure you'll figure out how. Also, don't be too picky about which heater core you get, I recommend the Escort heater core only because it's the cheapest and smallest one I've found. If you can get a different one cheaper, or the Escort one is too expensive at your local store, get whatever is cheapest. More than $25 and your getting ripped, less than $20 and you've found the correct one.
While your out around town, stop at the hardware store and pick up 10 feet of 3/8" vinyl hose. That'll run you $2.50
Now you'll need a fan for that radiator get some cheap 120mm fan
Now you'll need a reservoir for that pump. Depends on your budget what you do. You can go to the hardware store and buy a sealed marine electrical junction box for $9, or you can grab a Tupperware container out of your mother's kitchen. Up to you. I'll assume your on a budget and go with Tupperware.
cheap eh
around 60-65$