Ceiling mount heater

My shop is 30x40, with 12' sidewalls and open overhead to an 18' peak. It is fully insulated on the 2x6 walls and ceiling. I have a built-in room going down one of the long sides, so my working shop area is 20x40 with all the overhead space. Temps out here are pretty moderate, lows in the 20's to 30's and highs in the upper 30's to mid 50's all winter. We do get colder snaps but not for more than a few weeks and maybe a couple of times a year. The shop is somewhat leaky, as the sliding door's gap pulls in outside air (the door gap is 75% blocked off when I'm working inside), and the peak is open to let out moisture.

That's a lot of back story, but when I retired and started playing with cars, my plan was to put in the old wood burning stove I took out of the house. However, as a short-term fix I put in a pair of 60" industrial ceiling fans to push the warm air down, and fired up a smallish (30-40K) propane heater. Much to my surprise, it keeps the place nicely warm, in the upper 50's to mid 60's. On milder days in the 40's, the 30K setting is too much and I use a smaller 9-15K propane heater. I haven't changed this set-up yet because it works so well. Good air circulation and insulation may help you a lot with your situation, whatever heat source you choose.