Good idea Rodger, man after my own heart.
Something that starts life as Minibus is such a good idea, or at the very least a crew cab, and much much nicer than a plain old van,
even stranger though, is that because they're not for everyone, you can pick them up cheaper than an equivalent van sometimes, have much better service records if they have actually been in contract, and not stood at the side of a hole in the road with the engine running for 8 hours stationary!
I've done it this way myself a few times now, and its tops.
if you need some seatbelted seats i have a few, and i have a few other accessories you might want to pimp her up with too mate, just holla!
Fiat Ducato, 2.8JTD is a good choice, they go well for sure. what sort of year are you looking for Rodger?