That does seem really tight. However, 10' walls with vaulted trusses seems like it would work just fine. Some places have max ridge line height restrictions that might make 12' walls a "no go".

I went with a 14' ceiling - as most two post lifts need 12' 4" and my four post lift is the extra tall version allows for an SUV under it - other things to consider is using high-lift garage door tracks. My shop is built like a house 2"x6" framing and heavily insulated - I also used 5/8 drywall

I also have very rigid design code where I live and I worked with an architect to make it blend into the neighborhood and we hid the roof line by making it look like a barn

Mine has 10' walls, 4-12 roof pitch with scissor truss, eave entry, high lift door.
30' long + 2 foot overhangs.

Doing it that way left the somewhat unlikely future possibility open for either two hoists or a loft/mezzanine across the side that isn't
occupied by the hoist.

I have forgotten my interior height at the peak but believe
it's around 14'6" to 15". Most vehicles (except for vans) will be taller in the "greenhouse"
area than elsewhere which the scissor truss accommodates.

If I was doing a flat ceiling I would want at least 14' in the hoist area, wherever that is chosen to be.
12 is workable but it depends on what you're working on. For cars (only), you can probably get by with 12.

I'm not sure on the insulation, a spec of 2" without an R value given sounds inadequate to me (but I am from Michigan, we have to be picky about
that stuff or we will freeze). The first couple feet of my eaves are R14 to leave ventilation space for rafter baffles, the rest is R38 + I blew about 18 bags of cellulose on top of it all a little at a time as I closed up the ceiling. The walls are dense packed cellulose. hydronic radiant floor heat.

Consider insulating the slab/vapor barrier no matter your location.

By the way, you don't need to connect water to heat the slab with hydronic radiant.
You can do a self-contained system, fill it and forget it. Mine is set up that way.
I actually run a special anti freeze/water mix in it in case the power goes out and I'm not around, don't want it to freeze.

highly recommend www.garagejournal.com for ideas and to share your build if you're so inclined.

Good luck

here's my combination
40X50 stick Built
radiant floor heat ( worth every penny)
Walls - 9"4" (floor to ceiling),
EXTERIOR 7/16th osb covered with Tyvek,
INTERIOR 6" fiberglass insulation, 4mil plastic vapor barrier, 7/16 OSB, Steel siding
Floor 2"blue board insulation, PEX tube, concrete.
Celling 4mil plastic, 1/2" Drywall 12" cellulose insulation above
Two steel man doors Two 8X10 overheads R9 insulated.
Using a 24kW OnDemand water heater I keep the floor between 64-68 degrees which in turn keeps the room at 60degrees. If we have a cold (below zero) period (5-7 days) I keep the shop light s on which raises the room temp 3 degrees but the shop area has never been below 60 since the completion of the building.

Size of building not dependent (ceiling height, foot print) the most important (to Me) things to include would be radiant floor heat, vapor barrier which also acts as an air migration barrier and as much insulation as you can fit in the spaces. Keeps you warmer in the winter and cooler in the summer.
If you go with High ceilings traditional heat will eat you out of house and home, the space above your head (and un occupied) will be warmer than the space you will be occupying. Radiant floor heats from the bottom up and gets consumed as it rises therefore you stay warmer at less cost, traditional heats from the top down. Additionaly with radiant Floor there are no cold spots/Zones the room will be the same temp all around.
Anyway thats my

To get the door as high as possible for clearance, there's an option called "High Lift Tracks" that have longer vertical tracks that will get your doors closer to the ceiling. I think the radius portion of the tracks may be slightly different too, but not sure. I have 2 doors 16' x 8' & a ceiling height of around 12' or so. I did this for the same reason, more room so the doors clear the car on the lifts.

Will your ceiling be flat & parallel to the floor? If it is, no special items will be needed, but if the ceiling follows the angle of a truss, you'll need a different radius track to keep the upper tracks parallel to the ceiling & out of your way. I installed my own doors alone & it was fairly simple. You will probably still need the steel 90 degree angles, lag screws, bolts. nuts, & some misc hardware to hang the tracks & harware that comes with the door.

One thing to consider after you're done installing the doors & before you install a lift, is clearance. My garage doors clear the cars when the doors are open, & the car raised to the highest point on the lift. The door is parallel to the car's hood or trunk, & about 12" to 18" above it. My pick up truck has a cap, & my wife's SUV would be a different story, as the door would not clear the rooflines.

Before I ordered & installed my 4 post lift, I knew I had plenty of headroom to the ceiling. I used the max lift height, added the tallest car height I had, then measured the distance from the floor to the backside of the door when it was up. I'm not using door openers so that wasn't an issue, but if you have them, don't forget to see where the opener is in relation to where the car will be. Same goes for lighting.

I had room to spare, & the high lift track also keeps the top edge of the door from going further back into the garage. The distance above the door allows one panel of the door to remain verticle on the wall, thereby shortening the door's travel distance in the horizontal position. That shouldn't be an issue if you keep it close to the ceiling with the truss angle.