EXTJS 4.1 MVC & ASP.NET MVC 3.0

Project Description:
I need a base application where I can add functionality made in EXTJS 4.1 MVC & ASP.NET MVC 3.0 as the backend for all the JSON (data).

I need the base application to have a login screen with encrypted security, after success login (should work with SQL Server) then the main application UI is shown. The UI could be something like this (other designs are welcome):

http://www.aafrin.com/wp-content/uploads/2010/08/extjs-web-app-06.jpg

The application has to work with user roles, depending on the user role then specific buttons, panels, etc can be visible or enable for the user.
The user can change the theme color and the preferences of the applications and then saved into the db.

The base application must have a left menu. When an menu item is clicked then the content is loaded dynamically in the main panel.

The idea is to have good base framework application in EXTJS 4.1 with MVC pattern and working with ASP.NET MVC 3.0 as the backend for all the data transactions and that can be used for any required application with documentation explaining how to add or create new features or modules.