Why limit yourself to a 7.3 superduty degas bottle? Pretty much any bottle will work. How about a 6.0 one. It’s meant to stuff up against the fire wall. Or hell even a gasser 6.2 might work.
I would hazard that this ground is the hold down bolt for the alternator? What size fuse would you recommend on the power wire from the alternator. I'll look at getting this done next.Run the negative to the hold down bolt.