From the RV sales side of things... The business department where I worked had a menu of lenders, they would match you to your best situation, they get a commission from the lender. The cynical may say that they will show you the best commission for them, but really not the case. Credit unions were the last resort, they had looser requirements. After the credit union the buyer would need to make their own arrangements with either their own CU, or Vinnie on the corner.
In the past, I borrowed against a 401K short term, and then just paid cash later. Then again, I haven't bought anything over 100k. For that a big loan and somehow find the income for the payments.
CU's typically will not loan for more than 15 years, and now I would guess that term has dropped. The big banks would give 20 year terms.