You either install baseboard electric heat, or run duct work and install a heat pump. What's the room going to be used for? How many windows are there? Do you have the height to run your duct work? If it was me and the room wasn't going to be used a whole lot like a basement I would install baseboard and keep the stat down low and just turn it up when the room is in use. Good luck.
The room is going to be used for business storage / shipping location. So for 16-20 hours / day it would not be in use. But the items need to be somewhat climate controlled and when I'm in there, I would like to be warm enough to work (65 degrees or so).
There are two windows. One at each end. It is it's own building.