Transfer and Airside T3

Hello EVeryone
Im booked to go see my brother in Japan leaving on VS900 3Sep, I have a 4 hour connection from my BA flight and was wondering what I can do for the 4 hours, i hope to check in online the night before to save that hassle. Would you guys have any recommendations that i can fill my time with, as ive never flown from T3.
Also this will be my first time on the A340-600 so would anyone recommend a good place to sit for good views?
Thanks again!
Mark
Im booked to go see my brother in Japan leaving on VS900 3Sep, I have a 4 hour connection from my BA flight and was wondering what I can do for the 4 hours, i hope to check in online the night before to save that hassle. Would you guys have any recommendations that i can fill my time with, as ive never flown from T3.
Also this will be my first time on the A340-600 so would anyone recommend a good place to sit for good views?
Thanks again!
Mark