Customize WPML (Wordpress Multilingual Plugin)

We need someone familiar with WPML to add a customization that WILL endure updates and upgrades.

Customization would seem simple. We need to be able to INDEPENDENTLY set default language and language order for site visitors (front end). Separately we need to be able to set a different language for administrators (back end) and possibly, using the profile feature allow individual admins to change to any other admin language for the back end.

Ideally this would be created as an add-on plugin that can be installed on any site of our choosing.

Strong english communication is a MUST on this project. Would like to see this done in less than 2 weeks. Glad to provide server access for final testing.