I bought the 3221 model (lowered version) from Tweetys. Mine came with the hitch unit, the ball coupling adapter (that mounts to the king pin), and the standard coupling adapter (sleeve that connects to the GN ball). The newer models have a "funnel" on the ball coupling adapter. That's what will be included and that's technically all you need. Some may wish to purchase the safety chain package as well, but that's a separate item.
For the 2nd part of your question, the hitch attaches to the GN ball, so you don't need anything for the hole (the hole will have the ball).
