Is your Cayenne Turbo S optioned with the 380mm front brake rotor option? If so, you may be limited in your options. I haven't been able to find anything other than original Porsche rotors.
There's a thread on Rennlist where a fellow installed DBA brake rotors in what appears to be the 1-piece rotor, but I can't find the part he's looking at on the DBA website. I also don't know if the 350mm front rotor will work for your application. Edit: It looks like the guy who installed the DBA rotors has the Turbo model, not the Turbo "S" model. Sorry.)
(For reference -
https://rennlist.com/forums/cayenne-...nd-rotors.html - Look for post #13. Old thread, but may offer some insight.)
If you search the factory part number, 95535140261, AutoHausAZ has it on sale for $600USD each, but I think after taxes, shipping, duties, you're back at $1000 each.