How to heat

Wood stove will probably be my end choice depending on my budget. I plan on getting a fireproof cabinet to store my flammable chemicals. I do worry about the possibility of gasoline vapor From my parked cars. As far as insulation goes I know of closed cell and open cell spray foam insulation. The building company offered to insulate it (it was some kind of bubble wrap plastic) for a little less than 2k if I recall.