Hi mate,
I'm in a similar process at the moment where i'm changing my headunit to an aftermarket one, albeit mine isnt the cabasse 6 disk changer. My advice would be to contact connects2 who will be able to help you find the correct adapter.
In my case they have asked if i can email them a picture of the back of my standard head unit to help them identify the adapter I need.
I have also read on this forum that some leads will need extending for people with the 6 cd interchanger. Have a search, i'm sure you'll find the information you need.