I mean it's a truck, any reason you can't put a tank in the bed? A common upgrade in these cars is a 7 or 8 gallon trunk tank. It adds a lot of thermal capacity and allows you to add ice if you want. They're pretty much all made out of aluminum.
You can see some examples here.Ya that would be ideal and have thought about it. If I were to put it in the bed do you need a stronger pump since its further back away from engine bay?