Texas Tailgaters makes pits of all sizes and shapes and prices. I've got a large backyard pit that he made me several years ago that includes a 2'x2'x2' firebox, a 40"x2' round main smoke chamber, and a 4'x2'x1' upright smoke box at the far end. Most of it was made out of new 1/4" steel.
He's also made me a much smaller reciever hitch pit that works GREAT for tailgates and in the backyard for smaller cooking needs. It's about 4' long total including the offset firebox. You can cook directly over the fire or in the smoker. It includes a receiver hitch mount and a floor stand.