I'll second or third the Cruise RO system, ours is the 40 gal. A/C D/C unit, simple and reliable. Pretty much the same system as Kevin's. When anchored, We run the generator daily for a few hours to top off the batteries, so running the water maker helps put a load on the gen, that's also when we use high A/C use equipment. Coffee maker, microwave, washer/Dryer..you get the idea.
Rich is the owner, and has answered our calls right away, great customer service and probably the best price.
John & Tracey
" I can explain, but I can't make you understand"