I am using an F-450 with the PSD for a tow rig. It is basically the same as an F-350, but with a longer bed, a higher towing capacity and most importantly, larger brakes. The best option is the second fuel tank from Transfer Flow. The truck will now carry 80 gallons of fuel. This keeps us from having to stop every few hours for a fuel fill-up. Now we can roll on and only stop when mother nature calls! I have had the truck for just over a year and it has been great. I use it to pull a 45' Apache and a 36' Cigarette.