It most definitely sounds like the clutch on the compressors pulley. You could take your chances and get a compressor off of a salvage car and just remove the pulley and clutch then reassemble it on your compressor or just swap out the whole compressor.

I would say that if your air is working, keep your compressor and just swap out the pulley and clutch on it. You'll need a special tool to get the pulley and clutch off of the compressor but it can be done. I think Autozone has the tool and they loan out just about any tool you would need to work on a car for a small deposit which is refunded when you return the tool:thumbup:

For my H22 in the civic, I had to retain the civics compressor and mount it to the H22 with an adapter plate to retain A/C. The pulley's on the two compressors were not the same though so I had to remove the pulley from the civics compressor and the H22's compressor and swap them... it's really simple if you have the right tool. You definitely want to remove the compressor from the block though to make it easy to swap the parts.