How do I create a dynamic job ticket for Xerox printers?

I am programmatically creating PDF files in Python and Reportlab Toolkit, each containing several thousand documents, each document with a variable amount of pages.

My problem is that I need to instruct the printer which media type each page should be printed on (pre-printed letterhead for the first page of a document for example). It seems that I need to generate some kind of job ticket which hold this kind of information.

I've had some success with creating JDF job tickets, but these only run on my organisation's newest printers which run Xerox Freeflow Server version 8.

Ideally, I need a solution which also works with our Freeflow server version 7 and Xerox DocuSP printers. I have tried unsuccessfully to send JDF tickets to these printers.

Is there another type of ticketing system I could use, or a way to get all of our printers recognising JDF files?