Devsan - as a compromise, how about booking an emergency exit row. That way at least you won't have your knees sqashed into the seat in front of you for 8 hours.
I can't recall if the emergency exit seats have movable arm-rests, [although I am sure Tray Surfer will help], but if they do move, you will be in a win-win situation.
As an alternative, if you are travelling with a few family members, why not pre-book 3 of the middle 4 block of seats [eg DE & G] ? Unless the flight is full, I would have thought that it is very likely that F will not be booked, and thus you will have the empty seat next to you that Tray Surfer recommends.