IB if you can get a booking ref from your travel agent, you should be able to reserve your seat 11 months in advance on line.
the upper deck PE on virgin is good. only 2 seats on each side, so nice wide aisle means you can easily get past the food trolleys if you need the toilets.
also luggage bins between window seat and window give you easy access to your bits and pieces without getting up from your seat. very quiet up there as well. have a great trip.