I would be interested in travelling to Tibet as well, however won't be able to make it in October .
Did you guys concider the fact that the 1st whole week in October is a national holiday in China? Pretty much the whole country is travelling around at that time, so it might be difficult to get tickets if you wait too long. In addition, Tibet might be swamped with Chinese tourists. If you are lucky though they all left Tibet by the second week .
I would be interested in seeing your pictures and to get to know your travel itinery as a reference for my future trip down there!