Here’s my husband’s opinion - he used to work for a livery company (limos and such) and is very good at working on cars. (He’s in charge of all our vehicle maintenance.

)
He votes for the van. Stay away from the limo.
The van is 10 years newer technology/ modern fuel management system.
Limos are made by coach makers (not GM, Ford, Chrysler) therefore they are custom vehicles that have many unique problems that can’t be fixed at any regular service garage.
A 12 passenger van is built on a truck frame and will have heavier duty components.
Note: The higher mileage van will have maintenance issues such as radiator, water pump, suspension issues none of which are a huge deal, but would need to be addressed.
Hope that helps.