IBC totes for tank and beds, 55 gallon barrels split in two for beds, old bathtubs, hot tubs, 5gallon buckets, there are plenty of these items availible for cheap and sometimes free if you look hard enough. Tell people what you are doing and see if you can get parts and pieces donated for your school project. I would be able to help you in setting this project up if you need a hand. Shoot me a line, I live right down the road.