@Bill Hanlon: That is a good idea. I had not considered making a shelf to go above the tank. That might just work.
@moparguy: At the moment I have a badly mounted, worn out split bench from a 90s truck in that maroon color everyone had. I am not sure what seat I am going to end up with yet, but I generally don't like putting things under the seats in my vehicles because they tend to roll/slide out at the most inopportune times.