I hope I'm not looking for a one-eyed cat here.
I would like to find the most efficient heat pump with propane auxilliary heat for those rare occasions when the outside temps are in the mid-30's or lower. This is for a well-insulated two story 2000 sf house. Ideally, a 14 SEER or better for air conditioning and 3 or better COP for heating. I would prefer R410 refrigerant, if possible.
I would also like a variable-speed air handler and compatibility with a dual-zone installation.
Who makes good units, and which model? Yes, I've read the old saw that installation matters, and I agree. But so does the hardware, which is what I am asking about.