After much reading and research, I have decided this setup will just have to do on my 07 4X2 Reg Cab:

Terra Grappler 265/70/17 mated with ProComp 1089's 17X8.

I am assuming this is the BIGGEST/WIDEST I can go WITHOUT a lift or leveling mods??

Your vast experience and knowledge is appreciated before I give a merchant the chance to pick my pocket!!!

 

What is the backspacing on the wheels? If it's close to the oem backspacing (5.5 inches), you should be fine.

 

The Pro Comp 1089's have a 4.5" backspace. Still work?

 

It'll be tight because that wheel will stick out 2 inches farther than your oem wheels. I think they will fit. You may need to get a leveling kit.