Update OpenCart Statement Script to Send Statement and Invoice Layouts

We're looking for a Developer to help with our OpenCart website. We have a Customer Statement script on our website. It allows us to create a customer statement based on their purchases with us in the form of Order ID and Order totals. This works by auto-selecting a customer from the database, check order statuses and then choose a start date and end date in order to find all orders within this time frame. We are looking for a developer to extend this scripting now to add the following ability: 1. Create a list of customer accounts so that we can use either the 'auto' select to pick 1 customer or use the new 'list' of customers to check the required customers to generate the statement. 2. Add an additional facility on the page to 'check' invoices too. This will then create a PDF document containing the statement layout, followed by the invoice layouts which make-up this statement. There should be two buttons. The first that generates the PDF for downloading to the computer. The second that gives the ability to email the customer. This should then be emailed to the customer email address which is saved to the customer database table. Having used Freelancers in the past, we have the two functions of Statement creation and Invoice to PDF email, already existing on our website, so we are looking for a developer with the ability to produce the above requirements.