if you don't mind going slow in the mtns then a gasser will do you. If you enjoy keeping up with traffic on 6/7% grades up to 17 miles long then you will want the diesel. Personally 99% of my towing is in the mtns on steep grades. I think my diesel will have a much longer life under these conditions than a gasser will have. And I'm not holding up a 2 mile jam of iritated traffic.Most of my towing is on 2 lane rds.
Diesel is the only choice for me. The truck sits until I hook up the trailer. If it were my DD I would not be so inclined. But I'm satisfied with a 14 yr old truck with 157K on it that was bought with cash 8 yrs ago for $17K. I don't think I'll be upside down in any way.
Everyone has a different situation. If not they would only offer 1 option. Buy, drive what you want. Just keep that gasser out of my way on those long steep grades, please.
Carry on.