Per flysfo.com website, the T1 would be fully opened in June 2024. AS should be moving to T1 and opening its new lounge later this year. You would have a choice of AS, AA (T1) and CX, BA (IT-A) by the time you fly in January.

In terms of age of the lounge, AS >AA> CX >BA.
In terms of food offering, CX>BA>AS/AA (we don't know what AS would offer yet, but I wouldn't hold my breath on anything extravagant since it's a domestic lounge).