Great start on the CAD work!
Thoughts?
With what you have so far, you have a "cooking area" and a "firebox".
Have you considered going "vertical" with the smoke box?
Kinda like a "Bandera on Steroids"

That has been done before and seems to work great.
It should be cost effective to just go "up" with a door in the front and as many shelves and square feet of cooking area you want.
Same firebox, same support system, just more cooking area for the $$$.
Looking good--keep us posted!
TIM
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"Flirtin' with Disaster" BBQ Team (RETIRED)
FBA and KCBS Cook and Judge.
Former owner of a WSM, a Smokey Joe, a Charbroil Commercial gasser (junk), the legendary "StudeDera", a FEC100, a Fast Eddy PG500, and Sherman the Wonder Trailer.
Now cooking with a Yoder YS640
Proud Pellet guy cooking on real wood.