I use those cheapy blue-green RV type ones. they are 6 gallons and I carry two per trip. I keep mine inside the cab so they dont see too much abrasion. I'd imagine they would tear fast if mounted like a jerry can.

I might look into those surplus water cans. <img src="/forums/images/graemlins/kewl.gif" alt="" />

96 Montero LS 24V DOHC 3.0L.
98 Montero 24v SOHC 3.5L, factory rear locker, Winter/tow package.
63 Jaguar XKE 3.8L FHC
2000 Mercedes-Benz e430
07 fj cruiser