VW sold a Eurovan in Canda w/a 2.4L 5 cyl NA diesel. Economical but slow, I've been told.
'93 diesel Canadian spec Eurovans can be imported relatively easily (compared to most non-US vehicles), but there was also a 95-97 commercial van diesel w/a different engine that is NOT import-friendly, or so I've been told.
I've asked here and at The Samba about TDIs in Eurovan and the basic response from those who know more than me is "nightmare." None of the TDIs that were sold in the T4 van (what the Eurovan is to the rest of the world) were sold in any vehicle here, so you'd might as well try and import an entire vehicle, which you can't do.
If you really want a TDI van, putting a TDI into the previous generation (Vanagon/T3) is much more common and has been done.