I owned a 2000 Excursion for many years and pulled a 7500# TT and a 24' 9500# enclosed car trailer with it. I made absolutely no suspension mods to it, just made sure that the equalizing hitch was properly adjusted and the trailer and Excursion rode dead level. They are wonderful towing trucks and the last of the real HD SUVs made. Mine had a 7.3 PowerStroke engine. The only chronic problem I had with it was that it seemed to want to pop an alternator about once a year. I alternated buying a lifetime warranty alternator from Advance and then from CarQuest (now the same company) so that I could just swap the alternator if it failed while I was traveling and then turn it in for another one at the parts store. Also, don't experiment with slotted/drilled rotors. They were a bust and I found that OEM spec disks and pads worked better than any of the supposed "high performance" brakes. The drilled and slotted rotors actually fractured between the holes. The V10 is essentially the 5.4 with an extra pair of cylinders and they've proven to be pretty robust engines.
Mine had 185k on it when I sold it and it had a lot of life left in it. I think you'll be happy with it.