A lot of your decision should be based on what the usage of your rig is, meaning ratio of daily driving to wheeling, and how much you're willing to trim if you run 35's. I'm on 6" of lift and 33's and actually want to go down. My line of thinking has changed over the years. I now feel that the best route is minimal amount of lift needed to run the tires you want, keeping the rig more stable and your COG low. There's a guy out this way right now doing a custom build with hp44/9" combo and he's only running 3" of lift and trimming for 35's. It's a sweet build.
And I agree with what was said above about tire size and axle choice. Most guys that run full widths do so for the benefit of running 35's or bigger. If I was going through all the effort of an axle swap, I wouldn't be doing it just to run 33's. Your stock setup can handle that.
If it were me, I'd go with the 4.5" lift, the full widths, 35's, and trim and bumpstop accordingly. Just my opinion.
