I have a Gear Vendors OD and love it. I also have an exhaust brake. I turn off the GV when using the exhaust brake and I have no problems.
The Gear Vendors is an extremely stout piece. Drag racers use them. They are just weak in the opposite direction.
If used properly they are great units. My truck has a tuner and injectors and I run it hard in the mountains at 22,000 pounds between truck & trailer.

 

From what you write, I'm going to guess that you have no real experience in moving a load that big and heavy. That's not an insult, mind you, just an observation.

You only need to move the trailer one time, and only 400 miles. There's no need to spend tens of thousands to buy a truck, insure it, and all the other stuff that goes along with it.

Go to UShip.com, and hire some one to do the job for you. I bet it will cost you less than $1,000 and you're done in a few days.

Sometimes you're better off hiring out some jobs, as much as we like to be self sufficient.

 

Thats sound advice.

 

You could pull it over flat land if you take it easy. If you're talking mountains or serious grades, it'd be cheapest to have it hauled. If you plan to move it around (camper use for instance) step up to a 1 ton and a suitable engine and transmission.