My job is working on vans and if anyone asks what I'd reccomend it's Transit every time. They're certainly not free from their problems but the only probs I see with them are due to being way overloaded (clutch and dmf doesn't like) or being driven round town (egr faults from coked up). I did 100k in my last one and thrashed it about, never had any egr probs.

I did have a vivaro before my two transits, used to kill my back driving it. The brakes are so rubbish too. I only work on newish vans and on Vivaros I've done loads of clutch slave cylinders, gear cables and front shock top mounts.

What sort of age/mileage are you looking at? Thing I've found with the older ones they get past 80k and you start to have major probs like diesel pumps, turbos and gearbox failures.