domepiece
+1y
The york compressor is about the best and cheapest. $20-$30 at most salvage yards and are on most older cars. I believe porsche's had a serp belt on the ones they used. Or you can machine them for a serp belt.
There is also one out there called a Tecumseh. It is made of cast iron or steel and weighs a ton compared to the York which is aluminum.