In this section, this broken record continues to spin... If your going to be selling in your local area know the health department rules.
I purchased a trailer, with an open porch back in 2013. Slapped a Pitmaker Vault on the back for space considerations, added a grillmeister for Dogs and Burgers and submitted my plans to the City.
Here in Houston, any"wood burning appliance" must be in an enclosed environment. So, I basically had to build walls around my"porch". But wait there's more.....
Because my pits were now in an enclosed space, I now needed to have an exhaust fan for EACH! Well, the grill came out and was sold and one fan was added for the vault. Dollars were adding up.
Knowing what can or will be approved can help you in your decision. Also, as has been mentioned, pits like FEC's and Old Hickory's / SP's meet all the criteria to easily pass inspection.
Good luck in your journey!