I think PAF should stick with current aircrafts procurement plans for operations and developments purpose, whereas, it should procure atleast 2-3 squaderns of the best in business from the west for learning and first line of defene of the PAF.
For this purpose, options could be, Rafale, Eurofighter or Gripen, and if u r able and ready to pay in cash the full amount u'll get the stuff.
and if PAF is not going to opt for any western fighter soon (which is the most probable thing to happen) then they should seriously invest in SAMs , but state of the art long range SAMs like S-300PMUs or S-400 and must go in a joint venture with China to develope its own SAM system.
To be honest JF-17 doesn't seem to be a dream fighter to me, it could be a reasonable alternative of F-7s because it has BVR cpability, but i doubt its performance in real time war...