The "not Delta" comment was more the fact DL does not fly there I think, but you can get an award through SQ (maybe KE too if you're adventurous ).

SQ is probably slightly better than QF based on anecdotal evidence, but QF is non-stop ... so whichever works for you (looks like SQ is 95k in biz or 130k in first, roughly equivalent to QF through US).

Your next step is to see if you can book them, maybe one of them is unbookable (availability wise) anyway making it a moot point which you should choose.

BTW, if it were me, I'd splurge and try and get First (and settle for Biz if I had too). It's only another 60k-70k miles.