Not sure what smoke woods you plan on using but the
BRITU rub is a fantastic rub for pork ribs with most smoke woods. Straight hickory can overpower it though, but a blend of hickory and lighter woods is typically ok.
I have no idea on how many pucks you need.
You definitely will want a drip pan in there.
ABTs are great. There are about a thousand different ways to make them too - limited only by the imagination really. Some use cheddar cheese in the cream cheese, some use a soft Mexican cheese (Casero or Panela), pieces of fancy sausages rather than little smokies, mini-meatballs, etc...