Blank canvas, steel sided 40x60 pole barn. Thoughts on insulating, electrical, heating???

Think about setting aside one area for a 'tool crib' for things like engine hoist, floor jack & jackstands. pot sandblaster, etc. Also build shelves in there for tools you do not use often. It keeps them all in one area when not needed so you do not have to keep moving or keep tripping over them. Put your compressor outside, build a little closet for it made from same material as your siding. Wherever you add your sink, get an "eye wash station" for it . Pretty inexpensive and you will appreciate it someday. Stock some first aid stuff - more than ninja Turtle band-aids close to the sink.