Quite simply, no 747-400s are available for purchase from Boeing, period. The 747-400 production line is sold out until 2009 with freighters, at which point serial production of the 744 family will end and production of the 747-8 family will begin. And the first year of that family is also sold out as freighters.

Phillipines does have four 744 passenger models on order, but they will never be built and Boeing has already assigned those production slots to freighter models. The only source for 747s for AS is new-build 748's starting in 2010 or buying an existing 744 and converting it.

Neither of which is going to happen.