Good choice. The 18th row is always a good option on the 77W. You might get a little bit less recline (maybe a quarter of an inch [?]), but there’s a divider behind you so you will not be disturbed during the flight.
I once sat in the 16th row because of the unlimited legroom, but it can get very cold since you’re sitting right next to the emergency exits. From the possible options you have I would stick to the 18L.