Am I missing something here?

Looking to redeem an MP award ticket this year in C on a UA partner or *A airline. Based in Japan so fly NH a lot and am aware that they have their new seat on NRT-LHR routes. But wondered about other options...

Also, wouldn't mind trying out the A380 LH but these are not flatbeds right? OZ is also possible but again, their new flatbeds are not on the LHR routes as yet.

This then leaves some quite long routes as the only other options, right? ie. SQ, or Emirates?? Am I missing some more options? Who would you fly? many thanks