My shop is 30x36' attached, 2 garage doors, 2 window, 10ft ceiling. One 12k Fujitsu cooling the shop, and temporarily cooling my attached home (Approx 1300squft). For your shop I would do (2) 9k Fujitsu units, 9k should do it, but 2 units would give better heat distribution and redundancy; I have taken in consideration the roof is not directly above the shop. The upstairs, (1) 9k Fujitsu, should be plenty considering your insulation. Mind you the high efficiency units I have put out more heat/AC than they are rated for.