My modifications are a superlift 5.5-inch, 33x12.5x15 tires on 15x8 (3.75" backspacing) black steel wheels. I have regeared to 4.56 axle ratio. I am prety happy with the results. I don't wheel to hard or to often. This set up is pretty much maxed out, I could go with a 35-inch tire if I really wanted to, but it would be hard on the stock D-35 axle.
If you wheel fairly hard and often and want to go with a tire larger than 33-inch, then you should consider a custom front suspension and steering system. A Dana D44 or D-30 is what most people use. If you do a search there are members doing the swaps right now with photos and detailed descriptions. The advantage is increased ground clearance, suspension artliculation, and axle duribility. The disadvantage is the up front cost.
The best advice I can give you is to use the search feature on this site, talk to (PM) members that have the set up that you are considering, make a plan of what modification you want to make and that you can afford, and get the best set up for your driving habits. Good luck.