I am looking at moving from OSE to the ZCA Basic to gain the backup and mobile functions. Since I am only using 4 actual users ans a few aliases, it will be more than enough.

So what would be the best approach? I have another domain that I was going to add to the system so my thought was:

Setup the new ZCA with the new domain.
Upgrade my ZCS 6.x to 7
Migrate the existing users and domains to the new box.

Does that make sense? Or is there a better approach?