I have had Jabsco(Par) pressure water pumps on all of my boats with excellent results. Currently, I am running a galley sink, two head sinks, two showers and a cockpit washdown all with the same pump. I have used this pump for six years and have rebuilt it once and also had a pressure switch go. I also use a 1 1/2 gal. pressurized expansion tank in order to keep the recycling to a minimum. I also have an in line filter
between the tank feed and pump. The pump is a Jabsco model 36900-1000 which is available in the discount catalogs for about $320.00. I also keep an extra pressure switch and service kit on board.