Back in the winter of 2014-2015, I installed the Teraflex Accessory Mount to my Teraflex hinge (look it up on amazon here).
This add-on lets you then install a hilift recovery jack and to that,Teraflex has mounting plates for your Rotopax containers. You can easily fit two of the 2-gallon containers on a hilift jack with the mounting plates.
Pictured is a 2 gallon fuel container and a 2 gallon storage box mounted to my Hi-Lift jack. You can also see the Firestick antenna which has a mounting point on the Teraflex Accessory Mount.