You'll need to panel the floor for a start. Insulate underneath while you are doing it. Make sure the panelling is well done so it takes your weight. Then remove the ceiling panels, get some ply drill it full of holes, knock in a load of t nuts attach ply to joist and stick on a load of holds. If its not too much hassle you could put in a small vertical kick board at the bottom. 6 ft isn't massive but should be ok if you have enough width