I finally made the decision and booked seats for myself and the mrs.

On the 77B configuration, I opted for seats 41 D/E because:

• Row 40 (exit row) was blocked.
• Row 60 (bulkhead, next cabin) is too much of an unknown as I could not find any photos or video.

On the 77Y configuration, I opted for seats 34 D/E because:

• Row 31 (bulkhead, mini section) seemed to have smaller leg space. 31C/H are shown* as having extra leg space, but I believe that involves sticking your feet under the curtain into business class. Don't be that person.
• Row 33 (exit row) was blocked.
• Row 48 (bulkhead, next cabin) is too much of an unknown as I could not find any photos or video.

For the book seats, found video material on YouTube, which allowed me to estimate 50cm/25" worth of leg space. That is not enough to stretch my long legs out, but it is ample space to relax and keep my bag on the floor, etc. I believe the seats have foldaway tv's which are perfect to hook an iPad onto. Near the toilet is a minus, especially for the night flight, but you can't wine's all.

During the flights I'll have a look at the other options, and report back here on my findings for the benefit of future travelers.