I'd like to use a 750 gal. rainwater cistern to supplement my irrigation. I've got a couple of zones with about 10-15 gpm. I need at least 45 psi to drive rotor heads with an additional 15 fthd. The cistern has a 2" drain on the side near the bottom. Should I use a booster pump or centrifugal pump off the drain, or can I install a submersible to drive the system (w/ no pressure tank)?