Hey Turbodeisel, like the wheels, I too am looking for a very similar setup now, keen on the pro comp 7033 series 17X9 with 255/70/17 (or 265/70/17 if they fit with no rubbing). did you have to do pinch weld and/or bolt trim with the pro-comps you put on your truck?
Negative tire offset means a better clearance from the UCA bolt as the tire is pushed out further fender side and away from bolt, but not too sure if the backspace clearance is sufficient at 5" compared to standard stock on 17" rims which is 6.5" (if it makes a difference at all), thinking about it a smaller backspace should mean less rim going into rotor side, hence less chance of issues clearing callipers...
These are the bad boys I am keen on : http://www.procompusa.com/prodDetail...73&plID=101928
Any info on your setup (lift, backspace, offset, wheels, p/w mod, bolt trim mod) much appreciated.