Pakistan has been working on producing AAMs and SAMs for at least a decade now, but through joint-ventures or as a foreign commercial partner. With AAMs, the South Africans offered us a development package in 1998-1999 in the form of cooperation in A-Darter, T-Darter & ramjet technology. We know that Pakistan took up assistance offers in precision A2G technology which helped in the H2/H4-series and Ra'ad ALCM. Denel offered a 'renewed' deal during IDEAS 2006 - also included Umkhonto IR & R SAMs along with the Darter-series.
Things to consider...the PAF said JF-17 will use a 5th generation WVRAAM. Given the sensetivity of such an advanced system on a main workhorse, it would be best that it is not directly imported. In other words the system must be customized by Pakistan to ensure its commercial nature cannot be used against us. NATO has been known to use methods of cracking source codes or screwing with weapon-systems of Iraqi fighters.
Of all known 5th generation WVRAAMs on the market & offered to PAF...of which I can recall IRIS-T and A-Darter - the A-Darter is the most realistic and feasible. For one the South Africans repeatedly offered us a space in the project. Secondly, the European IRIS-T will be a financial, political and technical pain...however NATO technology cannot be discounted. Hence the news reports of Pakistan negotiating with Thales for MICA...I don't think it is the missile we want. French-MBDA assistance in seeker, data-link & guidance technology would be much more desirable.
Clues that support my argument have already surfaced. For one the PAF revealed JF-17's HMD which appears to look very similar to the Denel (South African) Archer HMDS. Richard Fisher also claimed that JF-17 will use an "A-Darter derived WVRAAM". However the system PAF will use might be based off A-Darter, but it would be very different in some critical areas...probably guidance, seeker, data-link communication, etc.
The same applies to the BVR project. Do note that we Pakistanis have been hearing about a "T-Darter" project for years now. Well recently Denel unveiled the "T-Darter" project officially; and it will be a missile in the league of the MBDA Meteor. Maybe not as good as Meteor...but it may make use of ramjet technology and be a medium to long-range AAM - i.e. a contemporary of Meteor. Nonetheless...I have a feeling Pakistan is also involved in this project in a similar fashion as A-Darter.
As for SAMs...well for at least short and medium-range systems, I think Pakistan may use its AAM capability as a basis. The nature of A-Darter and T-Darter would allow us to produce our own effective and modern short & medium range SAMs. Not to mention the fact that Pakistan could have exposure to Spada-2000, Saab BAMSE, RAM and possibly even ESSM (as per pshamim on PakDef). So the initial basis is all there...we just need to put it all together. Plus other countries such as Turkey & South Korea are developing their own new short & medium range SAMs for land & naval use.
With foreign cooperation, IMO Pakistan will produce its own SAMs by 2019. I think a good bet would be to use T-Darter - especially if it is ramjet - and design a Vertical-Launch medium range SAM similar to the Aster-15/ESSM. This system could be applied to our naval ships as well as land based air defences. In fact, if we work on it in a similar fashion as the Israelis with the Barak-system, a T-Darter based SAM could have a range of 50-70km - giving us a singular HiMADS. PDMS systems can be developed using A-Darter...though I hope we could pull off a Rolling Airframe Missile like concept using A-Darter...
For long-range SAMs similar to S-400...we would probably use an existing and tested concept and develop it further locally. I think HQ-9 is the most likely choice, but you never know. I guess it would depend on when Pakistan wants such a system, if it it plans on inducting them in a couple years - then HQ-9 should be expected. If Pakistan plans to have it from 2019 or later, then I think a full local development of the missile should be expected. The ideal goal would be to produce a SM2 like missile, i.e. not resorting to the size of Chinese or Russian designs for long-range.
Though note...Pakistan might be on the ramjet boat and is working on at least turbojet technology - maybe even turbofan. Key would be to look at Turk-Pak cooperation, if the two countries decide to pear up on a long-range SAM - then expect an SM2-like design IMO.