I am developing travel website where users can search and book their travel deal. It goes like this: Providers are creating their travel deals (same as some blogger create blog in WordPress); Users book wanted travel deals; Providers, who have their account where they can see if users book their deal, are notified by the email and sms about just booked (sold) deal. Site is going to be developed using WordPress. Is there any plugin or module that I can use to accomplish this, or at least something similar to reconfigure and not to take this process from scratch?