Star Alliance - Best 1st across the pacific to ICN (between OZ, UA, new AC)

I have a variety of options for first class across the pacific to ICN from the east coast (award ticket).

SQ isn't currently available, but there are options using UA, OZ (via Chicago, JFK and LAX) and AC (possibly the new 1st on an A340).

Any recommendations would be appreciated. Thanks.

AC does not have First, only business.
AFAIK, they are still flying 763's on this route, and it will be another
year or so until they are all upgraded with new suites.
The 340's will not be upgraded.

Have you considered NH (All Nippon Airways) via NRT?
NH F is fantastic and would easily be my first choice across the Pacific.