Got 40K # tags on my Sportchassis. I would have to look to be sure on the trailer tag.

Had insurance with Farm Bureau that was CHEAP, then found out I wasn't legal driving out of a 150 radius so I changed it to Big Sky  RV Insurance thru Thum ins. They have to do the truck and the trailer. I had a better deal on my LQ trailer with USAA but had to "mate" it with the truck to qualify for the RV ins. USAA will not do a truck that big.

www.thuminsurance.com

Registration will differ by state, and also by type of plate. Here in Colorado a Recreational truck plates or farm plates are much less expensive than the commercial plate. Age of the vehicle also plays into it. 

Sorry, not a lot of help.