Need help to propose PHP based application to be automatically upgraded for many users

Propose a process of moving my proprietary PHP-based application, that I automatically install on cpanel web-host accounts for many users, over to whatever format/framework is needed so it can be made to via cron-job regularly check for updates, and to have the updates upgrade the PHP application installed whenever I release a new code I set as stable, and to have the users of the application get a choice for seeing the possibility to upgrade to any newer BETA-release for the same purpose of automatically upgrade their account. With update, I mean the PHP application itself should download its new php files and folders (and sometimes mysql database updates) and start to use these. Please comment on whether you think this is the right way of doing it. I currently use SVN for the code-base and I set up one cron-job automatically on the customer's account, so I can set up another if needed. I plan to encrypt the PHP-files on the users's account using WHMCS licensing + Ioncube decryption on the server itself, but I assume that doesn't affect how the upgrade itself should be done except it should fetch the encrypted files rather than the source code itself. IF you think this is awkward, and would propose a better solution, I'm all ears. I want your help stating what framework, process etc I should use, and document this. I also need the help of actually suggesting HOW I move the existing applications (what lines of code should go where, what files need to be added etc). Furthermore: I would also appreciate if you can comment on how to introduce the php application we have into the ZEND framework, since I like the ZEND TRANSLATE system ([login to view URL]) for providing the application in any language I may be able to add in the future. How do I go about starting to use it? (Again, what files need to go where, and what lines of code do I need to insert into my current PHP application)