That's a good question.
Well, ManilaBoy45, what's the answer?
According to AW&ST Feb 6th 2012 issue, the Philippines are looking to acquire two (only two?) Long range maritime patrol aircraft within 24 months of signing a contract. Supposedly a new twin-engined aircraft with at least 8 hours of patrol endurance. Those stipulations should narrow the field.
According to the same issue of AW&ST, the US has offered to deploy P-3Cs on a temporary, rotating basis.
China will not sit still on their territorial claims in the area, and their ambitions must be countered firmly.