Honda EU2000 storage box inquiry

Air Streamers........All hands on deck!!!!!! I just purchased two 2014 Honda EU2000 generators for my first road trip in my new,to me, Airstream. I was hoping that someone out there has gone through the learning curve on determining the best storage container for these units. I did see in a 2008 post that a 24 gallon Action Packer was the Bomb but testing shows that the new fuel cap design is problematic. Suggestions Airstreamers? Thanks Doug