I've never seen them sold as "smoked" units. HELLA makes smoked for the 3 and 5 series as well as som MB, Audi, and VW but for the E65 all the people you see with smoked tail lamps have them custom painted.
Since the E65 tail lamp unit is enclosed with LED's it would be very expensive to buy a new unit thats smoked (probably why no one makes it). It would be cheaper to pay a paint/body shop to smoke the lamps. My shop would charge about $150