About to fly my first oneworld flight in quite some time. Looking for advice on which airline to collect with.

BA SYD-BKK-LHR-FCO in Business Class

Don't know if I'll fly enough this year to get status, so my question may be, which oneworld partner is easiest to get status with, flying premium cabins?

I live in Asia. Travel a few times a year to North America. Fly Inter-Asia occasionally.

thanks in advance, stp