In My Opinion; The Van will need to carry a massive amount of spares. If you take 1 full set of spares for the shimano/sram - mtb, road, downhill, enduro and gravel. Then the same with tires, brake pads, grips, pedals etc. This is before you start stocking bearings, and other replacement parts. You will also need a full cleaning facility because people are stupid and at least 1 customer a week will have a filthy bike. Carrying water, hoses, dirty water storage and not messing the above mentioned driveway is a mission.
You will also always be under pressure on site in a rush to get it done. For me rather send someone to collect it. Take the day, source the parts(instead of stocking it all), have a good coffee while you work with space and comfort so that when you send a driver to drop it off. The bike has been sorted thoroughly.