We used Kashgar Guide for a trip along the KKH, up to Kashkorgan. The service was fantastic, from the email responses whilst organising the trip, to the guide and driver who were always informative and had a sense of humour. We saw some incredible scenery and really enjoyed our visit to the Kyrgyz family. We would definitely recommend Kashgar Guide for a trip along the KKH, and from what we have seen, for any other trip too.
Best of luck for the future.
James from UK!