Uhh never mind on the V10. My reading has it that the only Cayenne model with the 6 spd manual also had a 4.8 V8.
In my dreams, the Mercedes 3.0 diesel V6 found in the 320CDI would seem ideal.
OTOH, if I'm set on that, there's always an Audi Q7 with the 3.0 TDI.
2010 Audi Q7 Fully Loaded w/s-Line Pkg