We are putting a small restaurant kitchen quite a distance from the boiler room in the basement and it takes a couple of minutes for the hot water to get to the dishwasher. I would appreciate any recomendations for an economical booster heater for the dishwasher room ( two sinks and a dishwasher that uses 1 1/2 gal per cycle). Should we go with a small tank heater, or tankless on-demand?