A double garage is only good for one car if you want to work on it.
I did write a reply to all this but seems to have got lost in the ether, but I am going through similar process, except I am building mine now...
I keep swinging from having most things mobile to having the workbench made of tool cabinets, but actually you end up working on the car, which is the other side of the space, plus then I want to work outside at times.... It gets complex.
You can DIY fit an electric roller shutter door for less than 1K, insulated etc, I'll be doing this for mine, they aren't difficult, just need more than one bod.
Lighting will be low profile LED battens lamps, fewer shadows to worry about unlike spots, and they are only ~20mm tall so don't get in the way.
I'll be putting lamps on the wall as well.