We lose power often enough and long enough that we put a 12kw Generac stand by on our shared well. During the deep freeze when it was -12 for 3 days we had to drag the portable generator in my shop and put a heat gun on it to get it started, then drag it down to the well. The alternative was...
I make a few parts for obsolete machines. I love an excuse to use my South Bend 13. I make these replacement arbors for old Millers Falls hand boring machines. I make them in two parts with an interference press fit. I also make the square key for locking in the bit. After 100+ years of use...
Whatever you do, double it on the roof. I used roll fiberglass on the frame of my red iron building, then had 8" fiberglass strapped on the roof. It makes a huge difference in heat gain.
I started with a little Logan 210, about the size of the import stuff. My next lathe was a government surplus Sheldon 10"x54". Very nice little lathe. My keeper is a 13x72 South Bend. It has done everything I need. I have acquired a lot of tooling for it (the lathe is just the beginning)...
If you put your subpanel on a 90 amp breaker, you can run AL 2-2-2-4 mobile home feeder wire. Now all the experts can come tell you why you can't. Will you require a permit and inspection?
My solution. By the time I built my third shop, the loft and the hoist were requirements. Bridge crane would be even better, but would require a lot more headroom.