Input on new shop

[Lynn]

Need to pull my permit for the detached shop pretty soon.
Considerations:
1. It is for working on cars. I don’t plan to do woodworking, or other projects
I need enough room to accommodate two small rooms about 10 x 10. One will be a bathroom (no shower, just a toilet and a deep sink) and will double as the compressor room (walled off) and storage for welders and welding rigs. The other room is what I call the dirty room, which will have a small work bench, a bench grinder that will double as a polisher, my solvent tank, and a sand blast cabinet. Don’t want it too big, as I don’t want to end up storing crap in there. Just do the dirty work without getting a ton of dust and dirt on the projects.
2. Must have room for a two post lift. I already have the lift, a used Ammco ; 137 inches from outside of posts. Has to have room for another vehicle to sit on a flat, for those projects that will take two cars to make one.
3. I don’t want general storage (other than the welding equipment referenced above). Have plenty.
4. I don’t want it big enough to accommodate an “extra” car (afraid I will bring home another project that I don’t’ need… or worse yet, agree to let a buddy store one here). However, if I am taking two to make one, I obviously need a large flat area to place big parts while working on the two cars.
5. Has to be simple enough so I can build it myself. I have plenty of help, and can get electrical and plumbing permits pulled OK. My lots already have water, gas and electricity to them. In fact, there used to be a Sinclair service station on the other end of where I am building.
6. I prefer not to have engineered trusse. I realize that means no clear span of the entire garage. However, because the lift is already something I have to walk around, maybe it wouldn’t be a problem if the inner supports were close to the lift.
So, looks to me like an oversize 3 car garage will work fine for what I need. Has to have 12 foot ceiling in at least one bay to accommodate the Ammco lift.
I found some on line plans that look very close to my specs. 34 wide, 38 deep. Pics attached. First pic is the front of our home when it was in the historic homes tour. Rest of the pics are of the proposed shop. You can see on the last one, that I am considering building doors to match our home’s faux door, even though there are two buildings between the home and the shop. We own those buildings as well.
Where the “lift” sits can be moved a bit forward or back.
Obviously, I don’t want to be cussing those two 5 foot long walls on either side of the lift. Trying to figure out how big a PITA they are going to be. The ones up front and at the doors really don’t bother me at all. In fact the front ones are necessary for me to add the two rooms anyway.

Thoughts?