I am running 4.5" in the front and 5" rear. The fronts are 9.5" wide and rears are 12".
Get with Lynn or Dave at
www.hvydeez.com to get all the run down on moving the back spacing in or out for the ultimate look.
I think you are on the right track. To tell you the truth, I don't think my offset trailing arms are doing that much for me. For the most part it moves the Ebrake cable well out of the way. I could have gone to 6" backspacing on a 19" rim to clear the spring bolt and go deeper, but I did not like the tire height options in the Michilen for a 19" rim.