My opinion as it relates to the TC questions-
You state:
...later on in the future if I want a truck camper...
Unless you know that a future camper will absolutely fit and work on a 250 then get an 8' bed 3500 series to keep more of those future TC's on your list. Heck, you can even consider a SB camper on a LB truck bed.
This will be a daily driver (15 miles round trip to work).
I think gas engine is a good choice. A good 70 percent on my truck in sig was used for this type of driving and the diesel was too much. Never regretted the power, but more than needed when used as a DD as well.
I will retire in 5 years and so this may be my last expensive new vehicle.
I think the truck I suggest will allows this to happen with less possible regrets of purchasing a wrong truck for what the future TC might come along. Getting the LB 3500 will also be fully capable of your other toy- trailer needs.
JMHO.
