This is my take on the solution. Not saying it is the best, but I think what you want can be achieved with it. You could look into render_field (create_field in the non-pro version). You can add html to any field there.
You could create a form there with 3 buttons, which each have their own function and send a mail with wp_mail and hook it in the field you want it to show. Shouldn’t be too hard…
