Its a DIY project
youll get a complete tank with mounts from a truck wreckers, bolt straight up to the cahssis then all you need to do is plumb an equaliser line with shut off valves at each tank, it will draw fuel from the RHS tank and return the same, big diference is fuel level, park in a gutter for any length of time and watch your fuel gauge rise or fall
If you wanna be tricky you can plumb a fuel suction line with isolating valve on the LHS tank and put a "T" piece in the main fuel line just before the primary filter
works a treat