Thanks for the help guys!
Narita would've been the best choice for me, but sadly as I am redeeming from a *A partner SQ won't release any inventory on flights operated by the 77W and A380.
I suppose the overnight flight will be the best option. Getting to HND in the early morning can be quite difficult, and by taking the overnight I'll have more time to enjoy Tokyo. I suppose the lounge will be open for me, despite the flight leaving after midnight. Also it'll save me money on not taking an extra hotel night in HKG.
If book the cook option is possible for SQ633, I guess that means I can order a full dinner to be enjoyed on the flight, and still manage a few hours of sleep. The second flight SQ872 will be a daytime flight, so hopefully I'll manage to enjoy the service there.