I'm in the process of building an off grid home in Mexico. My system relies on a 12 volt pump, pumping out of an underground storage tank to a pressure tank. My pressure switch will be set a 30-50 psi, meaning when the pressure drops to 30 psi, the pump will turn on and fill the pressure tank until it reaches 50psi. I cannot provide more than 50 psi with a 12v pump.

My plumbing will be 1/2" PEX on a "home run" system.

I'm looking for suggestions for high quality shower valves that don't cause an appreciable decrease in pressure. I've had experience with some "water saver" valves that don't work well at all in the pressures I've described. If possible, I would like to buy old fashoned basic hot and cold adjustable valves without pressure balancing, temp adjusting etc., if they are still available somewhere.

Any suggestions would be greatly appreciated.