[67C10Step]

My 1500 5.3 4x4 would pull that 4500 lb trailer fine and it has a factory (adjustable) brake controller. I am always more concerned on the woah over the go so trailer brakes are a necessity. However, I think the 5.3 is lacking in the torque category and the 6 liter makes up a bit for that. In the hills or mountains you would not regret the larger engine.

Also, for pulling the rear suspension on the 2500 is more than enough to handle the load but is your trailer 4500 listed on the nameplate? Your actual, loaded weight will most likely be a good bit more than that once you get it loaded with all your travelling needs.

If you are going to drive the truck more without the trailer perhaps you would like the lighter truck better. If it's primary purpose is to pull your loaded trailer, I still like the 2500 option.