What class will you be flying?

I'd say AA is worthy of more consideration If you do a challenge (search at the AA board for lots of detail) you can get status quickly.

BA is not bad for premium cabins, but as Randy says it's bloody awful for discount economy.

QF is another option to consider, but there is no accelerated status programme I know of.

CX's programme is notoriously hard to earn status in, and my impression is that the awards are quite expensive. With your flying pattern I doubt they are a good option, even though CX Diamond is pretty much the ne plus ultra of FFP's.