If you’re building new and going with a double wide door get an 18 ft wide door. and a min of 24 ft wide for garage. Amazing how much that extra two ft does for you when parking a couple C bodies inside.
I recently watched HumbleMechanic's YouTube series on the garage that he built. There may be some info in them that would help in your project. I think there are five episodes, most of which are less than 15 minutes long.
i just got a metal building 24x46 x12high walls with 24x25 enclosed and insulated was about 15.5k installed. but i got nothin about lifts or anything else.