Hi Jon
My 2c worth:
I have difficulty calling it a van. To me it is a ute with a canopy BUT having said that, if it is able to have adequate access from the front into the rear (ie like the H series vans) i would have no problem calling it a van.

Whether i could call it a Sandman, this could be difficult if they just had the one option or not.
Options could be:
6cyl van = 3.6l
8cyl van = Gen 3 with standard interior
Sandman = Gen 3 with full Clubsport/Senator interior & HSV tags