If I was Taiwan I would request for AIM-120D. These missiles paired with the F-16V will give the Taiwan Air Force a qualitative edge against the like of J-11, J-16 and J-10B/Cs. There are too few J-20 and is still questionable whether they are ready for prime time with its avionics and sensors.The PRC wouldn’t be happy if the US sold Taiwan a potato gun. It’s boiler plate.
In BVR, there are 4 variables that matter : RCS, sensors, missiles, and ECM.