Over the past few years I have heated a couple double garages I turned into shops with King Model KBP electric unit heaters hung from the ceiling in the corner of the shop. They work well in heated insulated garage in the Pacific Northwest and you can move jumpers to select alternate heat outputs. I used 30 amp 220 volt circuits and run them at full power but that would not be necessary. They just recover faster in the winter when operating at full power. I also purchased the in-line King thermostats from Lowes or Home Depot, again not sure which but think Lowes so I could wire in a remote thermostat. You can select a KBP model that comes prewired for a remote thermostat if you want or you can buy a model that comes with a hardwired thermostat and remove it so you can then wire in the remote thermostat. I rewired mine but recommend buying a prewired unit to preserve the warranty and avoid any wiring confusion. The reason I bought ones with built in thermostat is that I found good buys on them at Lowes or was it Home Depot and then again on Amazon.
Good luck.