Create an order form that saves the data entered to a database and POSTs it to an external form

The task is to create a responsible and embeddable (via iFrame) travel visa support order form (will have field checks via JavaScript) that would first save data to the local mySQL database and then submit that same data via POST to an external web form (all invisible to the user). It would then fetch the response from that external web form (html), parse the links correctly, and display it inside our own design on our own website. So basically, the steps would be: 1) Create the new design for the form using exactly the same details as in the original (external) form; Should be responsive and should be embeddable (via iframe). The form will get some of its details via a request to an external API (a list of countries and hotels) 2) Make it so that the data submitted using the form automatically POST that same data to an external web form (you will get an URL when doing the job). The parameters (URL) of the web form where the data is posted should be configurable (via a simple [login to view URL] file). 3) The script then receives the data from that external web form (it's going to be a confirmation of "success" in html form plus a payment button) and displays that information inside its own design. 4) The data that is submitted using the form is also recorded into a local mySQL database to tracking and analytics. Important feature: the form should be hack-proof and safe. ATTENTION: TO TAKE THIS JOB YOU WILL NEED TO SEND US A LIST OF THE MILESTONES FOR THE PROJECT (your own idea of it).