I would find a dealer that has an Escalade or suburban that has them in the rear. Sit on them for a while, and make sure they are comfortable first. They range from $250- $1000 on Craigslist depending on where you live.
I don't know the measurements of these seats, It looks like a tank might still fit. They fold flat and the brackets are designed to remove easily, you will have to modify the brackets to make them fit your needs.