Originally Posted by PresRDC
The easiest option, IMO, is AA or UA via ORD or (for UA only), SFO. Opens the possibility of leaving from LGA or even HPN , if either is more convenient for you.
Via SFO on UA you can fly JFK-SFO in p.s., probably the best Biz class product doing the transcontinental run, followed by a non-stop transpac. You get access to JFK Red Carpet and SFO's International red carpet club (UA's 2nd nicest after Narita probably).
Seats aren't lie-flat but you can sit upstairs in some very large legroom rows.
I'm also betting this is your lowest cost option.
Miles go to USAir, one of the OP's preferences above.