Need help building a simple website or wordpress plugin

General information for the website: Custom vacation packages Kind of development: Customization of existing website Description of requirements/features: Please don't apply to this job if you don't know good English PLEASE!!! I am in the process of building a website with WordPress. This website allows users to Create their own custom vacation packages. Here is the process : 1) There are three Horizontal list of products: Lodging, Vehicle, Tours. The user simply clicks on what product he wants from each horizontal list which goes to the shopping cart. simple. 2) Instead of having a BUY NOW button, i want a VERIFY AVAILABILITY button. This button will send an email to the website admin and keep the order in a "pending" state. 3) After the admin has Verified the bookings, The admin then changes the state from "pending" to "approved." This then sends an email to the customer that their bookings are approved and sends them a link to process the booking order and pay. I require a WordPress plugin for this or custom code.