Just buy the Audi box that it is and then you don't have to pay the premium associated with the name Porsche. It is widely available in Europe for just a few hundred $$ you can get one out of a FWD diesel A8 or something similar. Or just try this one, it is brand new New Genuine VW Audi 6 Speed Manual Transmission Longitudinal Mount KTU Code | eBay
Thanks for the suggestion. Doesn't look like it would fit my adapter though : ( Different bellhousing