Not sure about Missouri but in Pa. you have to keep little ones in child safety seats. So I would say start by adding lap belts to the existing seat so you can hold down the child seats. Add the roll bar for extra protection. I'm not sure that a S-10 or Cherokee XJ rear seat would be a good idea since they both fold down and come in two pieces. Maybe a front bench seat from a S-10, Commanche or similar pick up would be better. My kids really liked our XJ when they were that age and still love it today, 12 or 14years later. Good Luck!!/wwwthreads_images/icons/smile.gif