A good part of the fun in preparing for a trip like this is making all the preparations beforehand. I've pored over the kit taken by other long-distance cyclists - always a feature of their blogs.
We've also done some big cycles before, and have refined what we pack over the years.
This is what we plan to take (links to a Google Sheet).
Having discovered ThingLink on Rolling East's gear page recently, once we've assembled all the stuff I'll have some fun putting some visuals together as per this experiment: