Hi,
If you go in the Pc where you've installed the console under:
C:\Documents and Settings\All Users\Application data\AVAST Software\Administration console\Mirror\Install
or
C:\Users\All users\AVAST Software\Administration console\Mirror\Install
you can find the deployment package, or under the console goto ADMIN->SETTINGS->SETUP and follow the link under the button to download the deployment package.
and yes, you must insert the same license key under MAINTENACE->REGISTRATION, or simply save the license on your desktop and double-clik on it.
When the client is attached on your network, it take the updates from the MIRROR, if you're out of your network, avast takes updates from internet.
The best is install the client by a deployment job when the client is attached to your network.
The license key will install automatically.