Underbody fuel cell?

Looking for information on mounting a small fuel cell that will fit anywhere under the truck for a diesel heater. I didn't want an exterior Jerry can. Wondering if anyone has experience with a small fuel cell that fits underbody? Thanks in advance.

 

probably anywhere there’s room including factory spare area if you relocate it

 

That's seems like a challenge. Not sure how I'd feel leaving the fuel container under the truck. Maybe it's cause I didn't have my morning coffee yet, but I foresee challenges in filling it up with diesel from underneath the truck. Then I'm thinking about road debris hitting it causing leaks.

 

Unless you build something custom similar to the vehicles fuel tank instead of the plastic fuel container. May be a good investment if you're somewhere that's constantly cold and use the heater all the time.