Easiest is gonna be outta half inch plywood man make it 3 sided and a bottom. Easy to cut your shape u want and its stout. Use gorilla glue and one inch screws to assemble. But if you want metal I have built tons out of everything you can imagine and its boiled down to the lighter the better on your ride. 3/4 inch square tubing and 1/2 inch mesh is my preference. This is what I am currently putting on my ride.
