a 12 volt filling station pump

Censtar external gear pump have searched high and low for a 12 volt pump that will allow me to transfer gasoline in and out of my camper van.No companies sell a pump only just a gas station screwed into a 55 gallon drum! I want a 12 volt self priming,20' elevation draw to fill my vehicle from underground tanks and other vehicles when needed. But no companies sell such a unit so I will have to make one however I need a 12 volt filling station pump to start out with! Someone must know a make and model of gasoline pump that would work. So Help my fellow survivors!