The 2.4 duratorq is probably the slowest. Good vans overall but boy do they rust!
On the mechanical side of things..
When you view one - fire it up from cold. It should fire up straight away without issues. If it fires up the 2nd go then most likely the cam chain tensioner needs to be renewed for the newer version. This is a labour intensive job but parts are cheap. Tensioner works on oil pressure.
Glow plugs are a mission to get out if they break at the back of the engine.

Black smoke out of the exhaust is an easy fix with an EGR blank plate and inlet manifold clean out.
Avoid bump starting these (new models might be ok) but you can jump a tooth on the cam chain.
HTH