Truck Bed seats

I have a two seated 83' Toyota pick-up. I want to put seats in the bed. I have a camper over it. What ever I put back there would need to be properly mounted and have seatbelts. Anyone ever do or try this? If so i would appreciate pointers.

I saw this dude with a 93 s-10 extended cab with a camper top, he put a bench seat up against the rear window, facing the tailgate, then put two low back bucket seats almost to the tailgate facing the bench seat. then he put speakers and a cooler back in there, padding/sound deadiner, and carpet. everything is bolted to the floor of the bed. but its pretty cool. i wouldnt recomend that anyone ride back there on the highway, cause if your hit in the side of the bed, or you flip or something your passengers may be killed.