I guess you got this already, but I have a full 4" suspension lift. It is a complete Rancho system with add-a-leafs and cast iron riser blocks. I have RS9000XL adjustable shocks. I know a few guys that have run systems like the one you are considering, they have all complained about premature wear of the steering components and tie rods. I think those systems also tend to cause toe-in problems for some reason. If I couldn't afford a complete system, I would compromise on tire size, upgrade to the best shocks I could afford (which can be used with a full system down the road), tighten up my torsion bars, and ALWAYS use add-a-leafs in the rear to prevent the Cali-sag - not my thing, I like mine level under a heavy load. The main difference with my prescription is that you would not drop the torsion bars with the new keys, thereby preserving factory geometry. I have seen 33" tires stuffed in with this configuration, although there is reduced suspension travel and they are heavy on the stock steering brackets.
My tires are 33x12.50 BF Goodrich All Terrains on 16" aluminum Pacer bullet hole wheels. I could go bigger but don't want to add any more weight to the steering system.
cheers,
Stuart.