Know of a couple of dealers close to me who seem to selling plenty of vans. One deals in mainly over 5 year old, up on the mileage stock stock. The other deals in very late stuff with little margin in it. My choice would be to go with what the former does but to be honest, it's hard enough trying to buy 5 year old plus diesel cars that don't need a flywheel, DPF or EGR valve that have been looked after, let alone a van that has been used by an employee who couldn't car less about it.
On the plus side I guess your van man ain't as fussy. As long as the windows go down, CD works and it doesn't look like a painter's radio then it's chocs away. I guess also your van man isn't going to do the rounds and see what's out there, 'talk to the boss', consult those lovely folk at Parkers or bring it back if a bulb goes. Hmmm, someone pass over the LCV catalogue....