Re: Heating System
IT depends on your propane and electric rates. One set-up is to use a heat pump with a propane furnace. The better heat pumps with variable speed air handers can reduce the airflow at colder temps and provide warm air down to around 25F. Below that, it can supplement with heat strips, but still produce some heat down to 0-10F.
You can also look at multizone minisplits. These inverter driven system can produce excellent heating down to I think -10F without heat strips. Mitsubishi is one of the better known brands.
Finally, if you want a premium system, is the Carrier Greenspeed systems. These are very, very efficient, around 26SEER I think and not that far off a geothermal system without the cost and hole digging. They produce excellent heat and can adjust from 40%-100% capacity so you get excellent dehumidification and very even temperatures because they run almost constantly. They are the cats meow.
1925 Two-Story Stucco Beaux Arts Neoclassical