For historical and political reasons, I highly recommend you use a local Ugyher tour guide in XinJiang. The guide(s) I cannot recommend highly enough are Abdul's Travel Service (silkroadinn.com). They speak the language, know the locals and the province like the back of their hands. You say you've got one of Abdul's 5 brothers as your guide? No worries, they are all knowledgeable and all but one of them are named Abdul! A real boon for us middle-aged types with noun problems!
We took 2 separate trips to XinJiang last year (2009). The first, in May, was to the west and south of the province. The attractions we expected to "Wow" us paled in comparison to simple walks in old-town Kashgar, warming up in the yurt with the Kyrgs at Lake Karakul, the Sunday Markets in Khotan, the Talamakkan Desert and of course, THE FOOD!!! The photography opportunities are endless.
Our second trip was in September, to the northern and westerns parts, at a time our embassy was cautioning about travel in the province because of the "troubles" in July. Abdulwahab made our trip worry-free. In fact the only disconcerting parts of the trip were frequent visits to Chinese police stations for the once-over and the omnipresence of the Chinese army. We traveled to Yili (Yining) where we had the honor or staying with Abdulwahab's family. What a terrific way to experience the culture, food and hospitality of the Uygher people! His mother cooked a fabulous lunch for us despite the fact that it was Ramadan, and we broke fast with a huge feast along with his extended family. They were the most kind, genuine, gentle people. The food in Yili needs to be mentioned here: I have never had better ice cream in my life, and my travel mate ate a cumin barbequed fish that she said was the possibly the best fish she'd ever tasted!!!
The rest of trip to Kanas, though scenic and adventurous, was anti-climatic.
I have traveled the world, but XinJiang has really touched my soul. I believe a big reason for that is Abdulwahab's Travel Service. If the brothers can keep two middle-aged women happy and contented, they are doing something right!
Go to XinJiang - don't hesitate. It will change your life.
Look up Abdulwahab - You won't be sorry.