20x9 with a -12mm offset (4.5" backspace) would put your new wheels and tires where you want them.
For tires, I'd recommend no larger than a 33" tire until you install your lift.
305/50R20 or 295/55R20 would be good sizes to look at. These may require a little fender liner cutting or the removal of your mud flaps if you have them but that should be it.
Here's my titan with 6" lift and 18x9 -12mm offset wheels with 35x12.50R18 tires (+bushwacker flares). A 20x9 -12mm offset would stick out the same. (You'll have to imagine it without the flares but here's the pics)