Best option would be SQ's 77W/388 C to SYD. 1-2-1, big space, decent food and service. Reward - poor.
Second choice is TG's 77W FRA-BKK, lot of spaces!
CA's 332 has a flat business class bed - it's OK hardware wise. Avoid 744 from FRA. easy to find.
OZ - fly on a wednesday from LON and use their Smartium class - great.
NZ's 772 is ok, a bit narrow. LX's 343 is flat but also a bit narrow. good food. NZ releases nearly 0 seat for reward tho.
LH - avoid avoid avoid. you will be slipping down to the floor all the times.
Try TK but make sure it's the flat version on 77W.