I've done some 4-5 bone ribs that took about 4 hours at 200-225 to get to 130 IT. It depends on the weight, starting temp, etc. I always use a smoker for my prime ribs. Oak, Hickory, cherry - all work. I've gone 6-7 hours for a 7-bone rib.
All I put on my Prime ribs is salt & pepper, maybe...