Petroworks used to sell one... I couldn't find it on there site...
Description I found:
Weak link: Range of travel in the backcountry.
Models affected: All.
What happens: While Samurai motors use fuel sparingly, extra capacity is still appreciated on extended trips. As owners know, these small rigs do not have a surplus of space to mount heavy jerricans.
Strong fix: Petroworks offers a DOT-approved 15-gallon polyethylene gas tank with five gallons more capacity than stock. A 3/16-inch-thick, zinc-plated steel skidplate is included and there is no loss of ground clearance relative to the stock tank.
Contact: Petroworks.
