My friends just did a trip last year. They are world travelers--have been everywhere--yet said this agent planned a trip of a lifetime for them. I emailed my friend about who she used:
Kensington. Affiliated or recommended by National Geographic. They did an excellent job. Planned a trip of a lifetime for us. Great guides, hotels and activities and sites at each stop. Our agent was Anne-Laure Guesne (888) 903-2001
anne.guesne@kensingtontours.com. She is now a director in charge of their European team, but could steer them to the appropriate person.