Remember that the flight will be full, others may also have nabbed your prefered seat, seats may be changed anyway, and that status with QF/OW determines what choices you may have.

Given that, I would just grab the closest to the front and decide window or aisle, for most if not all of the flight the window will be dimmed and/or it will be dark out, I would take that into account. Aisle in the middle may be better as it is 50/50 if ONE person bothers you to get out. Whereas on the sides it is 100% that TWO people will bother you to get out.

Also your flight is in September, which maybe "soon" for you, but not for QF, who may swap aircraft types anyway. if seats are important, then you may wish to watch manage my booking to ensure you are still where you think you are.

Enjoy the trip!