I cooked with a guy that had a smoker like that Bewley, a lot like a JR, in that you have to feed the beast every few hours. They cook up some great food, for sure. (and yes, I know that at times it seems like I am saying I have seen or done it all, I assure you, over 35 years+, I have been around
). If it is truly in good shape, that would be a great cooker to base a restaurant off of. I still think a Southern Pride or Old Hickory can be a valid choice.
Marubozo, sounds like you have a good handle on things, I sure hope you succeed. For me personally, being able to talk with the pitmaster really adds to the experience, even if the BBQ is great, I still like to chat with the guy running the pit, if you are exhausted, that takes away from it. I think interaction with your customers is vitally important for a restauranteur to keep his business shiny side up, you can read the plates, but, that only tells you that they didn't like it, talk to them, and you will find out why. And you will find out what they do like, and you can push that as well. Being up all night takes away from that.