Hello,
I hope this is the correct subforum for this type of post.
Regarding Linuses new house: Why won't you install a heat pump instead of a new (I'm assuming gas powered) heater and an AC.
A heat pump can do ac + heating (it's basically an ac with reversable valves) and if you have solar pannels you're basically getting heating for free (Of course the heat pump has quite the upfront cost though) and it's better for the environment.