The ball can be purchased separately. Google "Friction Sway Ball Kit" and you'll find several sources. You'll have several options available as some bolt on, some clamp, and others can be welded. The one on our Avion is attached with self-tapping lag screws while the one on our AS is welded. Both of which work well.
As for towing to get bearing service and tires. If it were me I'd order the replacement ball and install it before towing.
Congratulations on the Excella.
"You wouldn't worry so much about what others think of you if you realized how seldom they do."