Wordpress-Forms with Referer-Tracking and PDF-generating

We need some kind of form-processor for a wordpress-website. We would prefer if the forms would be based on existing form-plugins like gravity-forms and only the processing after they would be send would be part of this project. But it would also possible to program them from the scratch, if there are more reasons to do so. - There will be three forms on three different subpages. Two of them are nearly identically. - All forms only containing some standard-elements like name, forname, phone-number, email, eg. - As mentioned above, it would be nice, if those forms could be generated by a standard-plugin like gravity forms. - If it would be possible to use gravity forms, then we would desgin the form first and after this we would give you full access to it, to use it for your programming part. Those forms should contain some mechanics after submitting them: 1. They should check if the entrys are correctly (which would be done by gravity forms itself, for example) 2. The submitted form should be mailed to me including all fields 3. The form should track also an id to a hidden-field, if the user came over a referer-link. For example: if the user comes to the page the referer id should be stored into a cookie for the case that the person comes later again to that page. Also it should be stored in the url/session or whereever it would be best way to store in wordpress, to keep the user tracked during his visit. We need this because there will be partners who will spread the link to the page, and this should be tracked, because they can participate on the filled out form. 4. If the user came from a referer the form should be mailed to the assigned email-adress for the referrer-link therefore we need a database-field, or a text-list, where a email-adress to a referrer-id can be assigned. 5. After all was submitted the results of the form should be rendered into a PDF. It's a kind of contract, where now forename, name, and all the other fields should be rendered into. 6. A Mail should be send out together with the filled out pdf-contract to the submitter of the form and a BCC to me. 7. The email should include some text like a "thank you" and a personalized text to the submitter which includes instructions how he has to handle the contract. 8. After submitting the form, the user should be redirected to a "thank-you" page which will inform him, that he will receive an email and shows again his email-adress. The whole thing has to be compatible to wordpress to keep it intact during next wordpress updates. If you need more information don't hesitate to contact me.