Dc pumps advertise more gph per watt, other than that heaters are still the same resistors, doubt there are much energy savings to be had there. You can get fancy with geothermal cooling or plumbing into the household water heater though.
I say use acrylic, keep the tank/sump mostly covered when you need to add heat. Will cut down on heater demand and reduce evaporation (rodi and possible need for fish room dehumidification)