Boat is 9m and will house me and one other person most of the time. I'm not very big on comfort or luxury, so that's alright. I've been thinking about the big cylinders to refill the tanks from, but on that size boat it would be too big a compromise on storage I'm afraid.
When in that area however 90% of the time we will be anchored in various places, but only going into port for groceries/gas/water/... I'm not sure yet how often that will be and how the diving facilities will be in those places but it's an option worth considering. Although it must be awfully painful to be on a sailing boat in some of the best dive-water in the world with all your gear there but empty tanks that only get filled once ever week or two.
As has been said by Dondon, the Bauers tend to be built to last, although there are some very competitively priced "other" units out there.
However, unless you have a high powered inverter, you aren't going to get a lot of 110 or 220 power; you'll only get 12v out of a basic boat electrical system. And the power will drain fairly quickly even with a good bank of batteries. So gas really is the only way to go if you want an onboard compressor.
