Which old iPod for full dash control on 2009 Cayenne?

[Behemoth]

I have a 2009MY Turbo S & it has the touch screen. I don't own iPhones or iPods but I want to buy an old device on fleabay so I can use the connector & get control at the steering wheel. Question is, which generations and models will work seamlessly on this car? I have a lead and the arm rest socketry for usb, mini-jack and a long proprietary Apple connector of some sort.

[Behemoth]

ok, I gave up on the 9 pin mini din Apple connector & am just using an old generic USB MP3 player which integrates well enough; charges too. That's me sorted for a long journey ahead, if I can still get petrol in France