Seat belts

[1968CHEVYC10]

I've got a 97 burban that just going to be a mud truck, so I wont be needing the seatbelts anymore. I've been thinking about putting them in my '68. I would like to at least get one of the lap belts for the middle so I can haul three people safely in my truck, and also if possible get the three point seatbelts, atleast the driver's side anyway, anybody done this? How would I attach the lap belt,? could I use the existing bolts on the floor of the truck or would I need new bolts so I don't exceed some kinda rating? and how bout the three point? no idea where to start there. thanks yall!