I used the Reese custom brackets for my F450 to mount Curt rails in the bed of my truck. The rails are standardized, so they will fit all brackets designed for mounting rails.
EDIT: Just read all of your post, I don't have first hand knowledge of the 56016 brackets or the rails. I understand overkill, but as long as the hitch is rated for more than your loaded rig, you should be good to go. Just my $.02.
2013 Bighorn 3370RK
2008 Ford F450
Full timin' and loving life.