[L78 Fred]

Lynn,

Happy Birthday as well!

A few comments after 37 + years in construction- I built 4 clear span garages for myself, and renovated/modified 4 more and have learned a lot after the first couple.
take any of this advice as you wish.
1) You can never have enough space.
2)clear span construction with engineered trusses is the way to go, you can use a box truss configuration to gain the extra height for the lift area
3)Pay the money for good commercial/architectural grade insulated doors, the size of the garage doors on both sides of your lift bay are too small- those sizes have been obsolete for 30 years, I like a minimum 10' wide ( most of my garages are 11' wide one is 12')and I use 9' or larger for flexibility use a torsion spring with a low head room kit to minimize the additional height of the ceiling.
4) love the idea of the compressor in another room- use "Rotten Cotton" between the studs to deaden the noise, and as noted make sure you have a window in your blast room for ventilation and or external fan
5) I use 4000 PSi concrete for my floors (6" use my lift) with wire while some people like fiber mesh instead of wire.
6) I highly recommend overhang of 12-24" on the sides/eves and gutters
7) Since you can't use 29 gauge metal (cheapest), Frame garages breathe the best and you could use vinyl shiplap/german siding, hardy plank (concrete board) shiplap/german siding, bat and board, or concrete block
8)6" walls are a great idea, and blown in irregular cut fiberglass insulation works very well, depending on your budget you could use a 1/4" foil foam barrier behind the exterior wall for additional insulation.
9) I like 5/8" X board Firerock drywall and there are some great other ones out there as well for any moisture issues and FRP ( fiberglass reinforced plastic) for the first 4' up for mechanical protection and looks good too.

more later if you want it- gotta help kids with home work

Best wishes
Fred