Digital solar charge controller

i need a solar charge controller which can be produced in third world for use by very poor house holds, it should have ability to operate on 12 and 24 volts with a current of 15~20 amps rated. should be able to work on three stage PWM and must have a digital display showing the state of charge. the charge controller must allow desired voltages to be set if different from default we are not experts in electronics our role is only that of a facilitator and technology transfer so we are open to discussions about the product