Create a form to populate a predesigned certificate with user data

Create a form to populate a predesigned certificate with user data. We will provide the certificate image with blank spaces that will be populated with specific user data, submitted by web form. The form and script should integrate with WordPress. If you have experience with Gravity Forms modifications, that's even better, as we would prefer to use the Gravity Forms plugin. We'll provide all the fields for the form. The form should be available immediately to the user upon form submission. The user should be redirected to a page that presents them with their certificate, with the options for the the user to download as PDF, or PNG file formats.