Excellent information and suggestions folks.
Some items I had covered from personal experience like door opening vs door size. Dad is a retired industrial electrician which will help on the electrical planning.
I didn't consider a sewer hook-up or pit until someone mentioned it. I'll also need to watch the entry angle as the foundation will be about 2.5 ft. above the surrounding area.
By code my living space is 800 sq. max but the garage is only limited to my bank account.
This is a substantial investment and I appreciate the input.