If you're planning on stump-jumping, rock-crawling, heavy-duty work, or building on a budget, avoid aluminum. It's more brittle than steel (cracks instead of bends) so the rims are made heavier to stand up to the stresses. But they'll still crack if you clip a curb or overload them & they're MUCH more expen$ive than steel. For mudding, street-driving, & general looks, I preferr my steel wagon wheels [img]/wwwthreads_images/icons/laugh.gif[/img] but most people would say aluminum.
I don't think the '80-96 body style was ever offered with 16's from the factory.