A standard pallet won’t work. You may need to add a second, smaller pallet to the original pallet for the kart to fit on it. I had a roller shipped to me last year, and the sender had to ‘make’ a pallet large enough to ship a kart on. The pallet was most of the shipping weight.
I didnt have to, but I did wrapt it in plastic as I did not what to expect. every shipper wil be diferent, so ask them what they use (truck, trailer, etc) to move the items.
The website is like ebay, shippers(mostly independent shippers) bid to earn your business. Make sure you select one with good feedback. Mine had 40 reviews, all positive, he provided his license, bond, insured, everything pretty legit.