Another LJ owner here. I have an 06 Ram 2500 diesel to tow mine. I have a 7k 18' dovetail trailer. I went with an 18' to have a storage box in front and chose the dovetail so I could unload without pulling the ramps. The LJ isn't built yet to do that but my TJ was and worked great. Usually load using ramps unless the trailer is in a position that the tail is low to the ground.
Once the LJ is built with tons and 38's I'll move up to a 20' 10k trailer with drive over fenders because the LJ width will be right at the width between current trailer's fenders. I want the extra length for a bigger storage box in front.
I think the minimum length with an LJ is 18'. Also get dual axle brakes. It's not much more money but adds more safety and less wear on your tow rig.
I too tie down to the axles using straps. Also make sure the jeep's front sway bar is connected.
Here's mine when I bought it.
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