I have found a great website to look at prior to that rather short trip to OZ !!!!
For those of us that cant afford Business or 1st class and have to travel like the good old convicts did listed is a great first point:
www.seatguru.com this tells you which sates to book and which to avoid
www.airlinequality.com this is really good as it give reviews, pictures, seatpitches etc.
One tip to note, on the jumbo there are 3 rows of 2 seats only right at ther back of the plane (this ideal if couple) airlines dont like to tell people about these we booked these seats and it was great coming back from Sydney to London as there is room at the side near to the window as the seats are designed for 3 rows. BA said that these seats are reserved for people with a medical condition, so i advised that i had a weak bladder and needed to get up constantly throughout the flight, imoral i know but at least i got a good few hours kip.