To ship your seats here is what I recommend/have done:
Go to Uhaul and purchase a furniture box.
Purchase bubble wrap somewhere else.
Bubble wrap the seats and place one seat all the way down inside the box, then, flip the other seat and place into the box upside down.
About $150.00 or so to ship via UPS or FedEx (of course, rates have gone up).
Hope this helps.
Ed