I'm guessing the 7500 lb towing number is pretty accurate, probably a 14,000 lb GCWR.
If it had the towing package it should be pre-wired to an extent. You might have to hook up the wiring to the fuse block under the hood for the 12V power. The brake power line should run from the same spot under the hood to the back wiring harness. You'll have to add wiring from the controller in the cab out to the wire going to the back and to the power source on the fuse block. I don't remember exactly what was provided to be honest, going by memory of helping a friend with the same generation. You shouldn't have to run cables from the front of the vehicle to the back of the vehicle however if it had the tow package which helps a lot and the power sources were ready to plug into. If it didn't, you'll have to run it all.
Should be a good tow vehicle. I 2nd putting in a transmission temperature gauge, add a bigger cooler if necessary.