Two very different games, so to speak. And most folks who do both have different processes and requirements, from one person to another. At the minimum for catering, you really need a great cooker, one that is large enough to handle a lot of ribs and/or chicken. Everything else can be managed on a smaller cooker. Then you need to cook, a lot, to learn how to run it, and what to do when it all goes wrong. Because it will.
That is a pretty good list of things you need to compete, I don't think you need all of that, but, it will all help. If it was me, I would get on a BBQ team and cook with them for a few competitions, get a feel for it.
me: I don't drink anymore
Yelonutz: me either, but, then again, I don't drink any less