I'd be inclined to go for the ductless minisplit. It would give you very quiet, efficient heat, with the added benefit of summer AC when you need it. Be sure to have a decent heat loss calculation done for the structure, to be sure it will give you adequate heat when you need it during cold spells. Either that or have a backup heating option, such as simple electric baseboard heating or a wood stove.
If you are residing, that presents a golden opportunity to do both air sealing of the exterior shell and perhaps application of a couple of layers of rigid foam insulation over the sheathing, with new siding applied over that. A good read on how thick to make the foam layer is here:
http://www.greenbuildingadvisor.com/...foam-sheathing. Adding insulation to the outside will reduce the heating load and make the interior much more comfortable in cold weather, besides reducing the size of the heating system required and the utility bill.