If you are limiting your travels to Tucson any of the Hemis will suffice in the 2500 (6.4 definitely better).... but living in AZ and traveling outside it’s borders you’ll appreciate the diesel. 14 and newer have been a phenomenal truck imho. Great mpg, great power, extended oil changes, and two fuel filters which is something that’s been needed since the 03 when the common rail came around.

08-12 6.7 I’d avoid.... especially since you emission test