Transfer tanks...anybody use one?

On one of our recent trips, I realized that diesel is a pain to find when your hooked to a 32 foot fiver. I ended up dropping the fiver off in a parking lot of a church and then fueling and hooking back up. I would love to find a 20 ish gallon transfer tank that I could put in the bed. All the transfer tanks I have found so far are in the 50 gallon range. The tank on my GMC is only 22 gallons so if I could find a transfer tank that is small enough to remove when I don't need it, but give me another full tank I think I would be golden.

I use truck stops for diesel so getting in and out is not a problem. Give "Transfer Flow" a call. They are located in Chico ca.