eccomerce web app

This web project entails having a separate eccomerce application from the companies main website. It is to be developed using php and mysql etc and have major security testing and encrypting capabilities. The application will need to have three login options administrator, user and client. The whole thing is fairly simple. The client will sign in or register for an account once signed in they will choose an option from the eccomerce section which rather than selling products will be selling a translation service so a calculator of the length of digitial audio and the time scale required ie (8hours, 24hours, 48hours etc) will set the cost. Once agreed and selected and paid for by the client world pay may need to have pay by cheque option) will upload the audio file (mp3, wav, etc). This will need to be encrypted or something to make sure it cannot be viewed by anyone else. The file will be uploaded to a specific folder within the account holders section. The audio file will be translated (depending on the time scale requested) by company and the word or pdf document placed in a download folder ready for the client to pickup from within their own login window. There needs to be emails and invoices sent at every step giving company and client notification when things are happening and the client can login and see the updates online and account service history profile etc. "Security is most important in this project." Administrator rights: Need to be to have overall control, to overview accounts and services and set emails etc. User rights: Can login to all clients to pick up files post files and change status of the project.