planning a tour of the silk road

I am inquiring about a custom tour of portions of the silk road in China. There would be 2 of us. We plan to arrive on August 28th in Beijing and intend to fly to Urumqi that day arriving in the evening. One of us needs to return to North America on September 10, so we would end our touring time in Xian on September 9th.

If possible, we would like to start from Urumqi with a visit to the Turpan valley during the grape festival. While in that area, we also would like to spend time in Kashgar and travel either to the Heavenly Lake or Lake Karakuli. Also while we are in that area, a visit to the museum in Urumqi is a possibility, though not our highest priority. We have a particular interest in experiencing the desert.

Other areas that we are considering include Dunhuang, Xian and perhaps Luoyang. We are trying to learn what we can about the many possible choices and would welcome your thoughts and suggestions about what to make a priority.

We have each been to China before on several occasions, but not to the northwest. So on this trip we would want to see some of the Muslim areas and traditions, some of the Buddhist grottoes, the desert, markets, and other places in these areas that you may suggest.
Because our time is limited, we are decidedly not interested in going to factories or other places making sales pitches to tourists.
As for accommodations, we understand that some of the areas to which we are traveling are remote. When staying in hotels, we would like a bathroom in our hotel room but the rooms do not need to be deluxe. Travel by train overnight is more than acceptable to us We would not have a problem with a sleeping compartment for more than two, that is, sharing a four-person sleeping compartment. We plan to limit ourselves to one suitcase each and one additional small bag to items that need to be readily accessible.
We require english speaking guide(s) Please forward suggestions for itinerary and cost as soon as possible.
Pat Smith