Nice size. Here is my .02 cents. I am not a mechanic but it seems to me like the lifts would be better side by side. Then you have ready access to both at any given time. Assuming that the Shop area and Storage are on the same level as the garage, are the stairs going to a loft area or finished office space / storage? I would consider a ducted heat system so you can direct heat into the shop and other areas more effectively. I think you will get tired of a 7' ceiling height pretty quick. Do at least 8'. I would also add a shower not much additional cost to do so.
My assumptions are that your 12' plate height is from the finished floor? If so do 6' walls at the storage and shop areas. Then add your 2x10 floor system on top. Then 8' walls around your second floor area. Standard trusses there flat ceilings. Then step down at the garage with your scissor trusses.
Added a really crude sketch of the exterior.
I like that idea and the sketch. However, I run into a couple restrictions.
1) Height restrictions in my subdivision.
2) My bank account and how much I can convince the bank to put in it.
3) I already thought about the shower, but realized it would not get used enough to justify.
I did however talk to the architect and we are changing:
1) lifts side by side
2) staircase is getting turned 90 degrees and going up to the west, using equal space from the storage room and shop area to do so in an effort to allow more space around side by side lifts
3) 12' garage doors being changed to 10' garage doors to give me more wall space
I'm also trying to decide on floor heat....
Thanks for the input!
Clayton