If you have 3.2 million AMEX points you should honestly just book something thru the AMEX travel portal w/ points. Pick up their Biz Plat card iirc for the 35% rebate on points used

For A380 I’d rank your options (in terms of quality of experience not affordability) as:
1. Emirates A380. Longest flight, most bling, unique shower experience
2. Lufthansa A380 to Munich. For the true AvGeek experience fly back via Frankfurt for the rare 747-8i as well & First Class terminal!
3. KoreanAir: The only remaining Asian A380 to LAX. Solid overall experience
4. British Airways… LOL

Bonus: Fly to Honolulu for the ANA A380 to/from Tokyo Narita, the special “flying Honu” turtle plane! Roundtrip fares go as low as $4k which would be 400k AMEX points, probably the most affordable option honestly