I think the camper package is going to give you a bed that is closer to the ground -- not just the one inch lesser tire radius -- but overall, front to back lower, closer to the ground. I have a friend with a 2015 F-350 SRW Crew cab long bed and the 20" wheels. His truck bed is very high, although I've never measured it. I have another friend with a 2015 F-250 with the smaller wheels and it is very obviously lower to the ground.
I have read many posts where people are having problems with their fivers riding nose-high with minimal bed rail clearance. I can understand how that is a problem for my friend with the F-350, but my friend with the F-250 wouldn't have this problem, although he doesn't tow a fiver.
Bruce