I don't know, and don't know if there is one. Your best bet on that size boat is one of the units that everything is remote mounted and you can mount items where there is space. The watermakers Inc. Islander series 700 GPD is probably a good choice and very simple manual operation. I also have a HRO Sea Recovery on another boat which works very good and once you set the pressure you can start/stop it from a tiny remote panel in the galley.
