Here are two more candidates of stark contrast:
Portable Heater, Dehumidifier, 12K BTU Heat pump/AC
Drop-in cheap heating (compared to straight electric), pretty, resellable. Suck fresh air from earth tubes, exhaust air indoors and out. Functions as a HRV. Very little sweat equity.
Window AC
The opposite of above. Dirt cheap, modify as you so desire. Get out the magic wand and make it do whatever. If it don't work, get your money back at the scrap yard.
The main idea is start small and cheap. Once you have something working in your house, the planning and decision process becomes short. Experience will tell whether or not this thing you have is for you or not. Since your house is well-insulated already, you shouldn't need a very large system anyway.