Starting from scratch! Which model of van do you recommend?

Carbon build up in the Sprinters seems be caused by excessive idling, causing the ERG, DPF to get clogged. I don't think it's been a problem with normal driving. MB recommends a good drive after an idling period to eliminate the ERG and DPF fouling problem.
Only time will tell if it becomes a problem with the under hood generators, and excessive idling.
I have read where a diesel fuel system cleaner was recommended every 10K if used for prolonged idling.
I'm sure this is all covered in more detail on the Sprinter forums.