Battery packs are fine if he finds it more convenient. Mains would be less upkeep. Not trying to necessarily add complexity but you might consider adding a solar panel to keep the batteries charged.
ESD is not very difficult to deal with. Mostly it can be squelched with a capacitor and a TVS diode. The real key is physical layout. You have to keep ALL the wires coming in and out of you enclosure in one area and protect all of them in that same area.
