I have an RDS tank as well. Unlike most, mine is used for gas. I installed a pump and pump fuel from the pick up tube on the top of the tank. Driving from San Diego to Dallas was a dream with the 80+ Gallons of gas on board. I put a switch in the cab to turn the pump on off as needed. We stopped when we wanted to...not when we had to.
When I was looking to order, I found this place:
http://3gtoolboxes.com/They by far had the best price shipped when compared to others (over 150 dollars)

