I'm looking at mounting 19.5" rims on my 06 van.
My bolt pattern is 8x6.5" iirc, not the metric pattern.
If my rims and tires fit you, I would have added incentive to make the switch as I have a decent amount of tread left.
Then again, I wonder if you would be interested in going the 19.5" route yourself?
Rickson Truck Wheels and Accessories