teleseminar series-create web appearance

Create a webappearance to host a teleseminar series, preferrably by integrating commercially available modules. Content management: Email marketing, opt-in page listing all the speakers and sign-up button asking for email address, autoresponse, info page (seperate or all in one) for each of the 15 to 20 speakers with embedded audio module for webcast (going dead after 48 hours), with a field to post questions to the speakers and sales button for special products (opening a new page with detailed description of that product, shopping cart. Box for comments, social networking embedded. Suggest established yet thrifty web hoster, webcast provider, email marketing partner etc. Customer wants easy access to change texts and update information alone. Since the webcasts will be in german, compatibility should be considered. Have I forgotten something? YOU tell ME, because I expect you to be a professional, who hasn't done this for the first time! Proof of previous work required.