Making a 2006 Caravan 8 passengers

Hi!  I need to make my 7 passenger 2006 Grand
Caravan into an 8 passenger.   I am hoping to find a
3 passenger bench that will fit into the place where
our 2 passenger middle bench currently is.  I have
read on this site that others have done it,  but
nobody has specified what year van they got their
seat from.  The problem we're running into is the
back seat of the 2006 is stow n go, but the middle
seat is not, so a 2006 doesn't seem to be the
answer.    Can someone who has done this please
offer some guidance? Thank you!