You won't get close with just a leveling kit and spacer! Biggest size that's been proven to fit without modifying the vehicle beyond a mild lift and reshaping the fender liners is 33" and even then there has been an occasional need to trim fenders.. To fit these 35s you'll need a body lift and do some body work.
Minimum 2" body lift and fender cutting. A full 3" Suspension Lift will help you at ride height (ie not moving on level ground) but hit a pot hole or speed bump and you might ruin your brand new rubbers.
You'll need wheels with different backspacing to allow the wider tires to not rub the frame. You will also need a body lift and suspension lift or titan swap and probably some trimming as well. I would say a 5" total lift with a little trimming. 35's are 35's, they don't come cheap on an X. 2wd might be different, but you still have to clear the frame and the fenders.
Thanks for all the info guys. I think 33's will be more than enough for my use. I was looking around last night and saw another 2wd X that is exactly what I'm after with mine. Prerunner style. Will mostly stay on road, for now.
As far as the Titan swap, do most guys go with the PRG setup or OE Titan parts?