Thanks everyone for the help. Think we will go on the train and just book tickets when we arrive in Yog. We are definitely excited about this trip.

Europe2011 - we arrive in Malng yesterday. On boarding the train we noticed the announce boards were showing the numbers of seats still available the trains - there were lots! Two of the Executif carriages on our train were all but empty. That said, always best to buy tickets on arrival "just in case"