Hi.
All these have 195/70-15 as standard, both 2 and 4wd vans.
I use 16" rims from a older Hiace 4wd (1989-1995) on my winter tires, 215/65-16. The old, smaller HiAce had selectable 4wd, 2speed transfer and 195/75-15 (I think?)
The old one also used same front/rear diff as a HiLux pickup so there is many lockers available

A dream car, but most of these have rusted apart now :-(
Here in Norway we also have some rules about campervans so the old type would never been legal anyway...
My van i the newer one with fulltime 4wd and no lowgear. But it's much better on snowy/ice roads, and like i said earlier: Offroading is strictly forbidden in Norway.
Anyway, my summer tires is 225/70-15. They have a very nice tread but for what i use this car I don't need more aggressive tread.
But, yes, for the look, I would love some AT or MT tires
For more hardcore offroad i used to use my Volvo L3314N offroader with 35"MTR.