On a building that size I'd forgo the mini split option. Too much equipment and unnecessary refrigerant lines, electrical, condensate lines, etc... would need to be installed. Overly complicated for what you are trying to accomplish.
You mentioned in your first post you might not want to deal with oil, propane, etc... However, if you can get he waste oil for free that is a good option. But what about air conditioning if you go that route; still gonna install the a/c/?
A ducted heat pump system would be best in Maryland in my opinion. Yes, you'd need some auxillary heat (it is installed directly in the air handler)...if sized correctly, a heat pump system will be all you need. Set the thermostat and forget it....simple, efficient, done. (no waste oil, no multiple evaporators, 1 refrigerant line set and 1 condensate line).