Noob question about release versions

We are just getting to the point of being able to release a game. We have a build for the Meta III and the Pro, and a build for the II. How do I get both versions approved as it will only let me submit one version at a time.  I'm worried that if I get approval for the Meta III version and set a release date 10 days out, then submit and get approval for the meta II version it will overwrite the Meta III version.  Also, I've looked everywhere and I can't find any information on patching and updating a game once it is released. Do you just keep submitting for review or is there a different process.

Any insight as to how to ensure that we have both versions available for users and what the update cycle looks like after release would be extremely helpful.