Building a bed rack

So I'm thinking about building a bed rack. I have it laid out so it will sit about 10 inches above the bed rails and bolt to the bed track. I have a bunch of aluminum 1 1/2 x 1 3/4 and looks to be just under a 1/8" thick. My question is to anyone who has done this is my aluminum going to be strong enough to support a couple of coolers maybe a shovel and high lift jack. I do not have and engineering degree nor have I had much experience with aluminum, always built stuff with steel

 

Tubing should be, flatbar probably not.