Compressed Air Source

I am trying to find an air source for the valve tool that is not overly loud or large. Ideally it would be small enough to fit in a shoe box and quite enough to run inside without disturbing people. I don't know how high the pressure needs to be, but I think 100-200 psi would be good. 100 psi is probably good enough for most of the materials we will be printing with, but most air compressors I have found have high flow rates that would require a reservoir. I have looked into sampling pumps, which don't work because they are vacuum pumps. Hargraves pumps and such usually only go up to about 30 psi. I have also tried asking Granger, McMaster Carr, and General Electric.

I think a refrigerator compressor might work, but I have had a hard time finding one. GE doesn't give out the specs of theirs, and Whirlpool doesn't make them.

I also think it might be possible to find a supplier of the pump for gas blowback Airsoft guns.

Another possibility is finding a regular old air compressor that is quiet and small.

Anybody have any other ideas?