Amana model PTH PTAC models with heat pump heating are the most common choice for professionals. There are 4 cooling sizes; The primary source of heat is the heat pump mode. The heat pump mode is about 300% efficient! There's a downside, when the outdoor temperature drops below 40F, the heat pump mode can't keep up and the electric strip heaters are energized. Still the best solution if you see more than 2 months of heating each year.