I have both - we did an expansion/renovation and the original house (basement/first floor) has the gas furnace, and the second floor/attic has the heat pump (it is also housed in the attic).

I hate the heat pump. Runs all the time. I would say it ran for three weeks straight during this last storm. Electric bills through the roof and our gas bills have essentially stayed the same since we moved in 22+ years ago (the old house was essentially uninsulated).

As much as you hear "it's so much more efficient," I really don't see it. Don't do it, OP.

I actually think OP could benefit from a heat pump, but they should also keep a gas furnace. It would give OP some redundancies in case either the heat pump or the gas fails, which seems to be the main concern.