you just need to draw out the panels, you can probably just make your own template, if it's a cut-specific pattern, i.e. the placement of the design matters
otherwise you can just design a fabric pattern to be printed and send that to your manufacturer
This is info you're probably going to have to pay for - nobody wants to give up info for free. All of us with manufacturers almost undoubtedly have spent much time acquiring their sources.
I'll let you know that (some) manufacturers can print fabrics. Get lucky and yours might too. Develop a personal relationship with your manufacturing chain and you'll learn alot.
