I did a lot of research. A lot. Many hours on the Internet pouring over tire specs, wheel suggestions, tire/wheel combinations.
My priorities were as follows:
The second major question was size. The stock wheels are 14inch. To come out anywhere near a stock ride on a 14inch wheel you have a huge sidewall. That's where I'm starting from, it's like riding on marshmallows. One of my major goals was to shorten the sidewall.
A lot of people have put 16 inch wheels on vanagons. Most of these wheels have two components I found undesireable. They aren't designed for vanagons. They are considerably wider than stock.
My arguement for rims is similiar to tires. The rims may be fine for a car, even a heavy car. But if they weren't designed for a van and its incredibly fillable cargo space, I don't want to bet my life on them. Now I'm not as conserned with rims because I figure they'll probably fail a little less castrophically, but I still wasn't thrilled with wheels that weren't designed for vans.
The other thing I didn't like was the fact that most of the 16 inch wheels were in excess of 7 inches wide. These wider wheels means you have a really hard time finding reinforced tires that even come close to the stock diameter. Not to mention the fact that your own wheels destroy your paintjob every time you hit a pebble.
Many of the people who installed 16 inch wheels did it for the wide tired look. They also talk about the modifications they had to make to make their tires fit. One page I read talked about taking a notch out of the battery box. I pictured how difficult it is to fit my battery in the box and immediately wrote off that suggestion. Other pages mention "rubs on X during full compression or compression with hard turning."
Many of the suggestions for 15inch wheels share the issues of design and width. There is however a solution that seemed to me the best of both worlds. The "South African" alloy wheels are designed for recently produced vanagons in South Africa. That means they'll not only fit well, but are designed for the weight. I didn't like the look of them in the pictures as much as some of the "car" alloys, but the warm fuzzy on fit and design overwhelmed the slight asthetic concern.
Wheel selected, I went on to tires. Finding a reinforced tire that had similiar to stock characteristics is a challenge. I found two possibilities on the web that seemed to match all my requirements. I called Century Tire, a local tire shop, that carried both brands and asked their opinion. I was impressed by the guy there because he knew what he was talking about, but he wasn't afraid to say when he didn't know something. I had found a Michelin Agilis that should fit, he confirmed that it should. I also had found a Nokian that he didn't know about. After checking, he found out that it is so new it hasn't reached the US yet. I asked for reassurances about ride quality and winter drivability on the Michelin. Then I ordered a set of the Agilis' which had to be ordered from the factory (those suckers are in short supply).
This morning I stopped by and had them install the tires on my new wheels and mount them. They looked much better on the van than they did in the sale pictures. The shorter sidewalls look more reasonable. I fired up the van and backed out of the bay, then pulled onto the street. Even at those low speeds I felt the difference in ride. The bumps were a little more solid and loud. But I could actually feel the turns now. The feeling of riding on marshmallows was gone.
I'm actually looking forward to being passed on the highway by a semi. Well, sort of.
The final results: