The part numbers for the darker R lights are:
5K0 945 093 Q (Inner Light)
5K0 945 094 Q (Inner Light)
5K0 945 095 Q (Outer Light)
5K0 945 096 Q (Outer Light)
You'll be looking at around £430 from a dealer and you'll need a set of adapters which are available on ebay around £30.
Not well up on these tail lights, what exactly do the adapters do or why are they needed? 
Connectors on your existing tail light (halogen bulbs) are not the same as the new LED units, thus the adaptors.
You also have to check if your BCM revision accepts LED, so u can remove bulb error light on your dash by coding it. Cars after Sept 2009 build has the correct module, for build before that you've to change the BCM unless you had xenons on the front.