My buddy is running that setup on his Montero. A single can adds alot of weight to the stock tailgate. Dual cans would stress it even more, but you could use an adapter like that and make an additional bracket to hold two can racks side to side.

Maybe your fabricator could make a swing open can rack/tire carrier/bumper like they commonly use on Jeeps?

On my buddy's Montero, we ended up installing a 20 gallon plastic gas tank from a YJ jeep with a homemade skid plate/mount.

Rear view, bottom is 1/4" thick, sides 10 guage:


Front side, fabbed and welded square tube mounting brackets to the front of the gas tank crossmember:


Rerouted exhaust pipe for clearance: