The most reasonable box set would probably be this:

-The Phantom Menace (Blu-ray upscale)
-The Phantom Menace 1999 (New 4K transfer)
-Attack of the Clones (Blu-ray upscale)
-Attack of the Clones 2002 (New upscaled transfer)
-Revenge of the Sith (Blu-ray upscale)
-Revenge of the Sith 2005 (New upscaled transfer)
-A New Hope SE (Blu-ray upscale)
-A New Hope OOT (New 4K transfer)
-The Empire Strikes Back SE (Blu-ray upscale)
-The Empire Strikes Back OOT (New 4K transfer)
-Return of the Jedi SE (Blu-ray upscale)
-Return of the Jedi OOT (New 4K transfer)
-The Force Awakens (New 4K transfer)
-The Last Jedi (Existing 4K release)
-Episode IX (Upcoming 4K release)

The theatrical versions of all the films would be included, but the cost of having every version would outweigh the demand.