I had the same truck, same year. SC 4 by 4. We weighed the same fully loaded with a Snowbird 9'6 slide camper. I used Vision 81 wheels and Michelin tires, same size as yours.
We are two normal size people only. I carried the Honda 2K in the back "seat" of the SC. I had Rancho 9000's and just normal F350 springs and Firestone airbags which you might need or you might not. The springs should hold you up fine.
The truck carried it proudly. Engine mileage was about the same as you.
You need to realize there is a very small market for that size wheel. 1999-2003 F250 and F350's only. They changed bolt pattern after that, so putting these onto your Ford costs a lot of money and there is not much hope of getting anything back if you sell. Research that point, but I know this is true.
You will likely never need tires again. You should rotate them front to back to keep wear even, but 60K on those tires is not unheard of. They are very heavy and really made me feel secure. I ran my tires at 105 psi, well below full pressure. A nice safety margin.
They do not air down. Not made to have pressures less than 75psi.
mike