Reread your post. Have I got a treat for you. Although my truck is older and a megacab, I have the same length bed as you. Here is a picture of a 2007 Bigfoot 15CF9.3 I almost bought. Gives you a reference of how much of an extension you will need to tow..this is the full empty/dry weight on my 2500's suspension. Loaded, I think you will exceed tire ratings as I did with my similar rated Wolf Creek with a 3000 lbs trailer....
You will carry all the weight on the rear axle. My TC doesn't hang this far off the back and my batteries are forward of my axle, where the TC your talking about has a single battery in the very rear as well as the waste tanks.
