Today I drove to a local compressor shop. Very nice guy. After talking about different options I had the choice between a slow running industrial unit and a "DIY and light industrial" one. He recommended the cheaper (faster running) device, and when I asked about the noise he even cabled both for me, so that I could listen to them. Needless to say he was right, noise level is about the same and I took the cheaper option.
The compressor isn't too loud, I've heard much worse, but as I'm living in a semi-detached house and want to work in the evenings, I plan to build a sound suppression enclosure for it.
