Sounds like a good project.
I used to cold smoke whole salmon inside a regular gas grille. I just used a large coffee can with holes punched in the bottom rim with a can opener, start it with a few charcoals in the bottom and once there were a few coals I would start adding soaked smoking wood (Peeled Alder in Alaska, Hickory or Mesquite down south). I would pick the smaller 3-4 pound reds or coho to do whole fish.
It usually took a couple days round the clock attention, or at least every few hours it should get some attention. Made some real melt in your mouth product.
It is not real technical, and doesn't have to be complicated to make something come out woth a good smoke flavor/ preservation.
1/4" Stainless screen on a frame is really good material for trays if you are doing fish.
I like the idea that something as large as your project would have different doors and perhaps removeable dividers for smaller batches, different cooking times or rotations for different serving times. You aren't always going to be feeding an army at one time.