Snow Lion is an excellent, well-run, Tibetan owned business. I am sure you will not be disappointed.
12

andreifox
Definitely Snow Lion. Their service fast and excellent. We was in Tibet in December 2011. They did Tibet permit for 3 days and sent it to our Chengdu Hotel by express post. Although their Tibet Guide wasn't very familiar with history of Lhasa he was perfect with history of other places out of Lhasa.
Pro tip