Stay away from ford diesel, on other hand Cummins is a good engine. Unless you going to drive 35K miles a year buy a diesel RV.
I pull my toy hauler with a V10 F350 ford with no issues, those a great motors.
Let say you hurt the diesel and is not hard to do, the replacement cost could be up to $16K, gas V10 is a $4500.
Fuel consumption will not effect you much if you drive 10K a year vs extra cost at front for diesel powerplant.
Diesel maintenance is a more than gas and anyone and his brother can work on the gas motor.
I got 347K miles on my 06 F350 V10 and this truck pulls full time,no issues except normal wear.
Don't be afraid of the V10, change oil and drive, those engines like clean oil.
In a past I had 05 f350 with 6.0 pos in it and by time I hit 100K miles I had 7 egr coolers, two turbos, countless injectors and 3 new engines installed under warranty.All repairs add up to total cost of $84K all covered under warranty, I guess ford make a killing on this $41K truck,