Bagged truck - How much travel
 

I am working out the rear suspension on my truck, and I am wondering how much travel is enough on a bagged truck. I want to be able to lay frame and still be able to drive comfortable down the horrible roads of Michigan. I will hit a pothole or too no matter how careful I drive.

I am looking at using the Slam specialty 7's. How much travel do I need to design for? I am thinking lifting the frame up off the ground 6 inches? Is this enough or should I go more?

Here are some of the rough sketches I have in solidworks with the truck at ride heigh (6 inches up), and then one with it slammed.