Need help. choice of towbar/electrics

I am changing my tow car to a (fordkuga) and need advice when chosing type of electrics. My caravan is 2006 and has twin electics 12n & 12s, I know that all caravans from 2008 have the new 13 pin system. So question is Do I fit twin electrics to the new car or do I fit the newer 13 pin and can I then fit/get an adapter? 

really need all your help and wisdom on this.

thank you in advance?