It is good to be organized and keep stuff from bouncing around back there. You might consider two 5 gal. cans instead of one 10. Scepter out of Canada makes a good water can in the "jerry can" shape. Then whatever mounts you build will hold petrol or water.
L43dean-1968 Fj40 LandCruiser,1980 Rn47 Hi-lux Pickup 4WD and 1985 Rn65 ExtraCab Truck 4WD. YEP!