If I were you I'd look at how often you are actually going to be towing that 8700# trailer.
I went through a similar debate with myself a few years back. I'm your typical weekend warrior/one or two big camping trips kind of guy.
When I looked at the fact that out of 365 days of the year, the RV was actually hitched to the truck for 5-10 of them, I went with the 6.4L Hemi gas engine.
More payload, way less initial cost, less complex, plenty of power, cheaper oil changes, and much cheaper repairs if it ever came to that. For the price of a fuel pump and injectors on a modern diesel, you could buy a whole new gas engine.
