UAC DayZ Mod Beta has been updated to release 1.4. Among the improvements, is the option to have The End mission be on continuously, rather than in a loop with the other missions, so it is always available to tackle.
UAC DayZ is a mod of DayZ mod that also focuses on single player/local play, along with multiplayer. You can easily run your own DayZ server to play local/single player. It adds it's own backstory with missions to complete, and an End/Final mission that can allow players to save the world.
This is for people who want to run their own servers locally, on a LAN, or on the internet.
UAC DayZ is more about PvE, and supports single player as well as multiplayer. It is built on Dayz Mod 220.127.116.11 and adds a lot more, focused on old-school survival sandbox though, combined with missions to have an optional 'End Game'. Please see Uacdayz.scoredoom.com for more information, and the promo video below: