Another possible option, Ford makes (at least I think they still make) small vans, not minivans but commercial vans that can have windows installed instead of panels in the back, and can be finished off in the cargo area, although it might be better to leave the easily cleanable finish and put your own bedding in. When I looked at them several years ago the back loading edge was higher than a mini van but lower than an SUV.
Ford Transit van, they still make them.