Next year I plan to fly from SFO to Hawaii for a short holiday. I would like to book proper lie-flat seats like on international business class, not standard US "first" class seats. Which airline would be the best bet?
You have a few options. You’ll want to seek the wide-bodies. Lie-flat is usually on United (777, 1-2-1, sometimes 2-4-2 but hopefully they’ve phased those out, 767, 1-1-1, rarely 757, 2-2, but beware some are recliners), and Hawaiian (a330, 2-2-2), mostly SFO-HNL/OGG. Basically, avoid narrow-body aircraft (737, a321) on that route. Hope this helps. Aloha!
The only lie flats are to HNL and sometimes to OGG/KOA depending on the time of year.
UA is usually running the high density 772s with the old J class lie flats....terrible product. They run a daily polaris configured aircraft (77W) but that changes from time to time. I would make sure you are booked on the 77W to ensure a better J class product. They do swap polaris 772s sometimes also but you wont know until the day of.
AS/HA runs the 332 - but thats an OK J class product. It is better than the high density 772s with UA but not as good as polaris. AS will not be running thier new 789s through SFO to HNL; however, if you want to try them, connect in SEA to HNL.....
Hawaii is leisure so they favor total numbers versus premium products.
I'll just add that there's no way to guarantee lie-flat seats to HNL from the west coast. Even if you book one of the above, aircraft swaps or schedule changes can happen. And if you end up in regular domestic F, you're SOL. No refunds, compensation, etc. If you backtrack to ORD, PHX, DFW, or the east coast, you'll be on a widebody with flat bed seats.
This may already have been addressed, but why do you need lie-flat seats flying TO Hawaii. Those flights are all during the day, and for a 5-6 hour flight you may take a nap, but probably don’t need a full bed.
Of course the return flight is another matter. Many of them are overnight, and that’s where I’d focus on finding lie-flat seats.
Imho
The SFO-HNL 09:30-/+ is the winner 99% of the time.
HNL-GUM is a daily 77W rotation and UA needs the ability to rotate an aircraft into/out of HNL from a mainland maintenance base, and SFO fits the bill.