Input on upgrading to 19.5's on my Super Duty TC forever now

The trick with those Ford wheels is that they only put them on from 1999 until mid 2003, then they changed the bolt pattern. The Visions also have special lug nuts needed to fit the wheels. I bought the good Rhino nuts for mine.

19.5's even at 75psi which is the lowest they will allow are still tough tires. You don't mention the shocks on your truck, but my adjustable Rancho 9000's used to feel pretty good at 2 and 1 when the truck was empty, and 8 and 10 with the camper on.