Large fan for my garage build!

[_Ogre]

without dimensions it's hard to see 40x120 out of your drawings

one thing to consider is heat, heating a 4800 sqft shop would put me in the poor house
i like to work in comfort aka sans down jacket

and unless your budget is unlimited 4800 sqft of concrete can get expensive
my choice would be to partition a shop that big into workable zones
pour a slab in half the building; living area and 2 roll up doors
i'd also throw a wall up in between door 2 and 3 and have that portion as insulated, heated working shop

the other half of the building could be gravel floor, uninsulated and unfinished
camper and boat storage and extra vehicle storage doesn't need to be heated
you can always go back in 10 years when funds are available and pour the other half