If a water source is above your home, but not far enough above it to yield acceptable water pressure, a booster pump could be the ideal solution to pressurize your household diaphragm tank. It could relieve you from needing to install a pump and extra cistern above your home for a gravity flow system. As long as the water source can flow into the booster pump, you can have good water pressure with very minimal power requirements. 12, 24, and 48 volts DC and 120 volts AC models are available with the DC models being preferable for operation within a couple hundred feet of your home due to more efficient energy use. Booster pumps manufactured by Dankoff are available.

Another  option is the Dankoff Slowpump.  It is DC powered and is a great little pump for efficiently moving water up to a cistern or may even be used to pressurize a small system.  It is capable of lifting water 450 feet if it is not pressurizing it, and is can operate straight off of solar (linear current booster recommended).