Implement a simple one page checkout to WordPress as plugin

Overview: [login to view URL] is a website for a business developing and selling a software product. The website is running WordPress. Customers can buy a license for the software from the website, here: [login to view URL] - the current checkout system is based on custom php code, written over ten years ago. Your job is to implement similar, a simple, one page checkout system as a plugin for WordPress to be used to replace the current checkout system. The payments are handled by PayPal, meaning the system must have PayPal integration so we will know when user has made the payment via PayPal (IPN). The system must automatically import orders made in the checkout system to WooCommerce. In other words, the website will also have WooCommerce installed, when user makes an order through this plugin, the order must be visible in WooCommerce with all the information but no, we do not want to use WooCommerce as the shop. For the full specs as well as the design (how the system must look like to the end user) are attached. Please read the [login to view URL] before making a bid. All bids done without reading the specs will be reported as spam.