We have an Echotec2 watermaker. They are based in Trinidad very near Peakes. Worth talking to them. Ours is 80l an hour and is an engine driven pump. The pump will take a second membrane and push out 150l an hour. I'm still considering doing this. The engine has to run at 1450 rpm which is fine for motor sailing, but changing the pulley sizes could mean you could run at higher revs.
There are obvious power advantages with non mains electric pumps. But I haven't fitted a diesel generator.
We're hauling out in Clarke's Court. Let me know when you leave Trinidad next season. It would be good to meet up. Ian
Ocean Hobo. SN96