Since you are going down south and will most likely be traveling on rough or no roads I would not use a mount that attached to the bed pockets. Newer trucks today are not as robust as the trucks in the past as far as sheet metal thickness. There are 2 types that I know of that you may want to look at. torklift is one
http://www.torklift.com/ and Happijac is the other
http://www.happijac.com/index.php/products/tie-downs I have used both and have no regrets on either. I am now using the frame mounted Torklift as my camper is a lot bigger now and it makes me feel better knowing that it is attached directly to the frame thus no damage to the truck bed Should accure. I should add that I didn't like the attachment method of the happijac's at the rear bumper and made some that are like the torklift that attach to the rear receiver of the trailer hitch similar to the Torklift. The bumper mounts flex quite a bit and will eventually bend the rear bumper on rough roads.
Both systems use a turnbuckle system with the front being spring loaded which is important. I still use the Happijac turnbuckles and they have worked well. This has been my experience and I am sure others will reply.
I would also like to add that I also drive on some very rough(off road) roads in the camper in my signature.
