Yeah but one of the nice things about my 550 is the 4WD- so commonplace on the 450/550 4500/5500 trucks. There's a scant few class 7 & 8 trucks with 4WD and they are extremely expensive to fix. I had a IH4800 4WD and it was more upkeep than I liked paying for. I frequently use my 550 off road pulling a trailer. In fact, all my loads of hay are loaded in the field and trucked off the field to the pavement and sometimes the field has snow, mud. A medium or heavy duty would be stuck-even with a rear locker. Been there done that. We end up pushing the trailer from behind with the farm tractor all the way to the pavement.
Now the OP may not have a need for off road capability. But my 550 with 4WD has saved my *** over and over again. Especially loading hay out of snow covered or muddy fields.
I do think an IH4XXX with a simple diesel manual trans set up and a flat bed with a ball, especially with air brakes would make a nice hauler IF you pretty much live on pavement, don't go off road, AND drive mostly flat ground. Put a trailer behind a 200-250 horse 4900 with a heavy trailer and climb a long steep hill...... You'll be doing 30mph at the top with the pedal to the metal and a 65MPH running start at the bottom. BUT they are relatively cheap, easy to fix and run a long time, tires last forever and they're pretty cheap ti insure.
Gotta remember the CDL if you're going over 26K and youll have to get used to cops looking at you very closely in some areas.