Just my 2 cents but I personally would not choose Basalt Black and Cocoa. IMHO they don't go well together. It's a bit like wearing dark brown shoes with a black suit. Doesn't work IMO. And even if you think it works (because you have seen this colour combination in real life with your own eyes), you should know that there are other colour combinations that not only work too but which work much better!
I have Cocoa in my 997.1 C2S and it goes beautifully with colours like GT Silver (which I have), Arctic Silver, Meteor Grey, Seal Grey (now only colour to sample).
IMHO Cocoa doesn't have sufficient contrast to make it work with Atlas Grey or Slate Grey either.
All I can say is that Cocoa is a gorgeous, warm, luxurious and rich colour - you'll love it - you will only notice the dark 'marbling' or 'veins' in bright sunlight. However, Cocoa is less flexible than a Black leather interior in that IMHO it goes with a much narrower range of colours.
However, this is just my subjective opinion - it's your choice and whatever appeals to you is what matters.
As for resale values, IMO there are 2 issues you ought to consider: 1) are you planning to keep the car for more than a few years? If so, don't worry about resaleability and resale values since your car will depreciate heavily anyway in the continuing poor financial climate (and OPCs will doubtless fleece you anyway on trade-in); and 2) surely your own pleasure is paramount rather than specifying the car to please the next buyer?
If, however, you only plan to keep the car for 2 years (i.e. for the duration of the warranty) or for the duration of a 3 year lease for instance before trading in, then you may well need to focus more on such pecuniary considerations.
Good luck - and don't forget to post photos when she comes
--
Rennteam Moderator - 997.1 Carrera S Coupe GT Silver/Cocoa, -20mm/LSD, PSE, SportDesign rims, Zuffenhausen collection