I've done the Costco pork belly with the ribs and they are lovely.
I took the skin off and just rubbed and put on the smoker for about 4-5hrs at 250f.
They went down very well
I have to say I really don't mind the pork belly with ribs from Costco. What I end up doing with it though is putting it on the rotisserie flat out with just salt and pepper on it and cook it for three hours. This way you get great crackling and the meat is soft and the fat melting. I guess you could put a bbq rub on there but sometimes plane and simple is good.