I would avoid storing fuel inside the truck, even the best sealing tanks always seem to leak, or you inevitably spill some fuel when filling or emptying the can. That smell always seems to find a home in the vehicle. I never wanted a bumper system with a spare tire carrier, so I got a Gobi ladder and mount two 2-gallon and two 1-gallon rotopax tanks on it; along with a trasharoo. See picture. It's a compromise...it won't work for everyone, but to date it works for me. The two things to keep in mind:
1. Keep a spare set of liftgate struts. When they go, they just go...not much warning. The struts definitely help with getting the gate open, but they won't hold the weight.
2. Order these to put on the struts when you need to have the gate open...
http://www.amazon.com/gp/product/B0002SRCYM?psc=1&redirect=true&ref_=oh_aui_search_detailpage
I have been very happy with the setup, others might have other needs that don't make this a viable option for them.
View attachment 182117
View attachment 182118