well Anti Body,
i don't think Pakistan has any indigenous A2A missile program. But chinese may in future be bringing something on the line or something similar to Python 4 as Chinese already have the Python 3 technology. But there is a talk that Pakistan may in future get IRIS-T which may be equal or superior to Python 4. By the way Python 5 is also there, an improved version of Python 4.
Well due to tankers practically the combat radius can be nearly doubled, but in Pakistan's case, i guess it will give more loitering capability to our fighters, enabling them to stay in air for longer period of time, also Pakistan can have now airbases as deep as possible, to be far away from Indian missiles range or would give ample time to PAF for reacting to any threat coming towards the bases.