There are five vans that fit your criteria, but you do need to check carefully as not every derivative will have the full 3.5t towing capability. This will be declared on the V5C registration document of any potential purchase, so make sure you check carefully. The models to look at are the largest version of the Ford Transit, the Iveco Daily, the Mercedes-Benz Sprinter, the Renault Master and the Volkswagen Crafter.