I doubt the F-16s would be very welcome - the PAF had more than enough trouble affording their F-5s, let alone the much more complex F-16. For strict air defense purposes, the best bet would actually be to pretty much copy Colombia - i.e. rather than try using expensive fighters, rely on a SAM network, and focus on the real mission, COIN. I would look very seriously at getting something like the Embraer ALX, or hoping for some donated American AT-6s.
Agreed with most points except for the SAM network.
Given the current threat environment, we have to eye-ball any threat before shooting it down. You can really only do that with aircraft. Furthermore, SAMs are single-use systems -- you can only use it for the air defense role. For the most part, they will be non-performing assets -- a waste of precious resources.
A multi-role aircraft, on the other hand, can be used for both the current COIN battle (especially if secessionists in the south get illusions of being a regular army again and start building fortifications like they did in 2000) as well as air defense.
Using lead-in jet trainers as fighter substitutes makes sense, and is actually what the Philippine Air Force (PAF) is doing at this time. At present, our precious few S211s are tasked for the air defense role. In the recent Talon Vision exercises, actually took part in air combat training with USMC F-18s.
For a lot of us, we'd actually prefer that the government focus on improving our aircraft detection network before moving beyond fighter substitutes. These have the added benefit of benefiting civilian aviation as well as air defense. (The PAF and the civilian Air Transportation Office have a "One Sky" deal with allows one other access to the other's radar data).
After all, what's the point of getting F-16s if you can't vector them to your targets?