Hey Randy I thought parts of your trail rig resemble a Maytag!
More expensive. Cut to order.
http://www.metalsdepot.com/
Most heating & AC shops have a variety of sheetmetal, and will cut and bend it
Ask them about "Galveneal". It is electroplated with zink as opposed to HDG (Hot Dip Galvanizing). It has a much thinner and uniform mat finish. It welds much much better than galvanized and has very good corrosion resistance. It paints nicely and doesnt require the prep that HDG does. It's great for floor board replacement and other areas where corrosion might be an issue. It will make a small amount of white powder (zink oxide) and fumes but nothing near as bad as HDG. Make it a proctice not to breath any welding fumes. A lot of the replacement body panels are Galvaneal.
I'm spoiled, my machinist friend brings me stuff from work.
After closer look, this appears to be what you'd want "S120 Cold Rolled Steel Sheet 20 GA. (.036 thick) Steel Sheet ". Correct? 4' x 10' sheet for $60 ain't bad, I don't think!
oh by the way......I saw your thread now.
Don't be following the maytag man around now.