IHMO, 29" (or metric equivalent) is the tallest I think most people will be happy with on a 4-door. I have them on my 5-speed and I'm on the bleeding edge of having too little power (ESPECIALLY when loaded down with camping gear). But, I do live where there are twists, turns, and some hills. That said, some people are happy as pie with 31" tires. If you go with 29" tires, you may not need a lift at all, and can probably stick with your stock wheels.
If you do need a lift, it will probably be because your tires rub the frame at full turn. I recommend Jeff's spacer lift - it's by far the most bang of the buck lift for your 4-door. If you can afford to shell out $700 on a lift, the OME is hands-down the most comfortable lift money can buy. Calmini, and body lifts are options too, but I don't prefer either of them. I've ridden in a Calmini setup, and it's nowhere near as plush as my OME suspension.