Find a team, at least the main members and then and only then think about the chronicle.
Also there are already a pack of that chronicle (what ever you choose) so then next question that you need to ask is, what will ours have that the old one doesn't. That may be less bugs, more customs, more retail like, more plug and play system, better efficiency, ...
If it is educational purpose, then how far do you want to go? just create the javadocs or remake the whole system, starting with diagrams of all types.
But the main point to start is to find and organize a competitive team for your goals