In order to recommend a anything on a garage build. There is a need to know where you live and what you are planning to do in the garage. Are you a “ hoarder” or are you like my co-worker is. He has nothing in his garage but his car and his tool box! I on the other hand have everything in my garage!
I built a 40x70 garage with 14 ft cielings. Should have built a 50x100 with 18 ft ceilings. But that’s me, I work on a lot of stuff, or at least I did once! Lol
Some things I would do if I had it to do over, besides size, is plan out where things go in the shop and put them in before the concrete is poured. That is my grinder stand, heavy metal work bench, so that when I try to bust something loose in my vise the work bench won’t give and anything else in the shop that you want solid. Also I would install short pieces of chain with a plate welded to the bottom and have a few links sticking out at various spots on the perimeter of the shop. I would use these for straighting frames, making pulls, etc. Pour the concrete at a very slight slope for wash out.
Just things I would do, I know it’s not for everyone. Bones