It would make a great combination. I have driven F250('99) and F450('01) . Both are great trucks; the PS 7.3 was a pretty good engine.
I happen to like the Cummins in my Dodge a bit better. In stock form, they are pretty comparable, but I like the power curve to the Cummins.
It is interesting I have heard folks talk about putting Cummins in other trucks, but never a PS in another truck...
I personally would like to upgrade mine from the 5.9 Cummins to the 8.9L that is in the new Fire engines our distrct has been getting. I got to drive them a little before I stepped down as a volunteer. They were NICE!