I had the same setup as well, but in the Super Duty, I used the back area of the cab and a extra wide and deep single lid box I got at Farm and Fleet years ago. I know that there are many other making this type of box. I still use this box, but it must be raised to fit the short bed truck, mine sit on top of my Trac Rack rail ( which I feel is a must have if you have a work truck, l carry everything from framing lumber to my 3 M TS rail on mine, great product. ), but a couple of pieces of 2 x will raise the box enough to clear the wheelwell. I don't carry my Systainers in my bed box, because I use the Dewalt Tough Box system for my heavy duty tools ( sawall and such) and my box fits them fine, but it's a bit of a pain in the ass at times to get them in and out. I live in the panhandle/ Gulf of Mexico area so I need waterproof boxes and the tools I keep in the Systainers can't handle the water. Also I take my more expensive tools in every night. Truck got broken into in my nice old Gulf Coast neighborhood, so they get put away every night.
