Minivans with collapsable seats

Hi yall. I'm new here and had a question.

I'm planning a long term road trip and am looking for a suitable vehicle.

My ideal would be a minivan with collapsable seats. It would give me slightly better mileage than a standard van and the collapsable seats would allow me to lower them to sleep/store things, or raise them if someone rides with me.

My question is, what makes/models of minivans have collapsable seats and how far back in years are they made?

Any help would be much appreciated.

I know the GM minivans' ( Chevrolet Venture,Pontiac Montana SV6, Oldsmobile Silhouette, Buick Terraza) have seats that collapse allowing you to sleep or haul items. These vans were produced in one way shape or form from 1997 to the present.The Chrysler minivans also offer seats that fold down and go into the floor. I'm not sure what year they started that option, but if I had to guess, I'd say around 2004-05