Although i concur with your idea to acquire a new Platform in Heavy Category, i will however push-back on JH-7A/B in favor of J15/16/11 chinese variants of baseline SU-27 fighters owing to the following:
1. Any new induction by PAF/PN will be subject to Chinese offering a soft line of credit, If Chinese do which they have indicated already, why not go for the top of the line multi role/ air superiority fighter considering the bottom line difference between JH-7 and J15/J16/J11D inductions would be within a ballpark of 1 Billion dollar give and take
2. J15/16/11 being mainstay platforms in PLAAF/AN, all the weapons, goodies, paraphernalia already stands integrated and vigorously tested, future weapons, software upgrades will entail automatically
3. J15/16/11 will relieve/load-share F-16 at higher ceilings, flying at safe distances, shooting slew of PL-15 at incoming formations at P-Max ranges will leave them disarray/defensive, creating opening for front line light weights to sneak in and go for the jagular