With BBQ, what you get depends on where you are. And by that, I mean down to the particular joint, not just the state or region.
A lot of the BBQ places here in Tx serve pork ribs, pulled pork, chicken, sausage, or brisket. Brisket (usually smoked & sliced) is probably king among the natives- it is so popular it’s starting to show up on cutting board stations in Chinese and Mediterranean restaurants.
But a sizeable number of places serve BEEF ribs, especially certain places in Austin. Austin also exposed me to Mutton ribs, which were incredible. (I’d be surprised if someone in your neck of the woods couldn’t make a killing with those.) And Turkey is becoming more popular here in D/FW, in no small part because of the larger numbers of Muslims moving to town. A good smoked turkey is an excellent substitute for ham in many applications.
And then there’s the exotic smoked meats that are becoming more common. Besides Buffalo, I’ve had ostrich, quail, boar, elk and venison at various smokehouses.
There’s a niiiiice family owned Mexican restaurant in San Antonio that serves cabrito (goat) a half dozen ways, including a slow-roasted rotisserie that is in-freaking-credible. Besides them, the Brazilians, Argentinians and other Central and South American cultures are showing off their flair with fire & flesh.