I have a 2006 Tundra with the smaller bed. I think it is a 6' bed. I need to save as much room as possible on the bed. The main things I need to find are the tank, and a cap for the bed. The tank: 100 +- gal Must fit directly behind the back window. A taller rather than wider tank would be good. The cap: Has to have strong, deep, side cargo shelves. Also have a large bin in the back. Any ideas on where to start looking?