I think in the 20 gal range, any of the oil-free compressors will be about the same unless you go with one from Harbor Freight, which I would be leery of. I’m talking Husky, Kobalt, DeWalt, Sanborn, Craftsman, etc. I have a 26 gal Craftsman that has worked well for me for my needs. Haven’t done much spraying, but as long as I take my time, it can keep up. A 20 gal will just require a little more patience during your occasional painting projects. If you can swing it, might look at going with a 26 gal if you’re going to much painting at all, but a 20 gal should be sufficient.