Good call to go gas versus diesel:  that’s what I would do, too, at least on the modern vehicles.  On paper the 6.6L V8 engine looks promising:  pushrod engine, iron block, No cylinder deactivation or even start/stop, lower compression, runs on 87.  And it’s paired to the 6-speed AT versus the 8 or 10-speed AT (which have had issues).  However, that engine is still fairly new since it was recently introduced on the 2020 models, so jury is out on how long it will hold up.  No one can really say right now.

If it were me I would look at a Ford Superduty with the true and tried 6.2L gas V8 mated to a 6-speed AT.  While in general, your fuel economy won’t be as good as a diesel, you also have so much less complexity   and repair costs when things do go wrong out of warranty.  Some of these modern diesels need their whole cab removed to do repairs (granted those are for the more serious issues).  The emissions really ruined diesels (IMO) after 2007 or so and made them all far more complex - no longer DIY friendly like they used to be before 2007.

They are better than most but I wouldn't buy one made after 2006 because of the AFM and other electronic nightmares.

Your fuel bill will be astronomical compared to the diesel.