Build Package Forwarding Platform for Existing Site

I am needing an experienced developer to create a backend system for my existing package forwarding company. I will like to maintain the front end with Wordpress, so the backend can be separate and can be linked to my existing domain. I have attached a document that will help you understand what exactly I need, and I also have 11 sketches I can send thru messaging that draws this out to help you visualize what is needed. We receive packages on behalf of our customers abroad, and we need our system to be built so we can check in packages to the customers. The customers will then be able to request shipment of the items they choose. Admins will be alerted of shipment requests, and will get the customers items ready and shipped. We provide two types of shipping services, our IN HOUSE service and DHL. We will create our own list of prices for DHL, so no XML work will be needed to implement DHL pricing. The most important thing is to make this as automated as possible, because our current system is very manual. Below is the feature list, but please see the document attached for full details. I will send sketches to prospective bidders. Feature List • Membership Plans • Auto-generate customer addresses when they register. Each customer will have a unique ‘Suite Address’. • Auto email customers when their packages move categories. • Auto text message customers when their package is moved to “Arrived” category. I did some research and it seems like Twilio would be the best service to use. • Search by Customer Name, Phone Number, Suite Address, Customer ID, Item ID, Package ID, and Shipment ID. • Ability to store customer credit cards on file so customers can opt in to auto renew their memberships. • “Balance Due” will be auto paid by credit card on file if not manually paid by customer within 14 days. • All “Picture Requests” will add $2 to the customers “Balance Due”. • 2 Admin Levels. Main Admin, and Secondary Admin. The secondary admin will only have the ability to move packages from Active to Arrived, and Arrived to Completed. They still have the ability to search records. • Invoices created automatically after payment is submitted • Auto-generate Customer ID, Item ID, Package ID, and Shipment ID. • When a SHIPMENT ID (when items are moved from “Confirmed” to “Active”) is created, a list of all items in that specific shipment should be created and accessible by a CSV export button for commercial invoicing purposes. I will only hire someone who has previously worked on a project similar to the details I have provided. I will need to see the example of such sites before I select someone to hire. If you have no experience with a project like this, then please do not bid.