Create a custom RSVP plugin (can be based on exiting plugin)

Hello, I would like to have a RSVP plugin with the following functions. It can be based or an add-on for contact7 or gravity forms. The function would be for a festival, where guest can register and add persons who will come. Because every guest will bring about 80 extra guest it would be needed that the guest can see who he already rsvp and who doesn't. Functions: - The client has be able to register and login with a email and password - The client but see a sort of client area, where he can manage their submissions - The client should be able to add or remove more than one submission the same time. (with a button: add more) - The fill in fields must be editable and extra fields must be able to add or remove them. (example: name, first name, address, pasport number, sex, ... - The organisator of the festival must be able to accept or decline a submission. - With most actions email must be send the client and organisator. (like new submission, submission accepted, declined, ...) - The plugin and emails has to be translatable with WPML - The plugin must be added thru the visual composer plugin (or a shortcode will be also okay).