Sharepoint 2010 integration

We need to integrate Sharepoint 2010 to create an Extranet to share documents with customer and provide this kind of services: * Auth with Custom SQL database for Extranet Customers * Let's able customer to upload documents * Let's able customer to search word in each customer area documents * Send an email after customer download a document * Send an email after customer upload a document * Trace on DB in a document has been download (when and how much) and display this info * Lets able user to change password From the backoffice: * Integrate Sharepoint 2010 with Office 2010 * Manage categories * Upload document * Search word in all and specific customer documents * Manage Customers * Batch Job that read file from a DB every xx minutes and upload automatically in Sharepoint with Customer & Category (this info are on DB) Other minor specific will be upload