I think that the PAF would be very interested in a EW fighter variant (the J-16D that you mention). However as we all know it is difficult for China to export J-16.In fact I'm quite sure, PAF would be highly interested in a Flanker type, at best the J-16/16D combo, however at least by all I know, China won't sell.
As such it needs other options and again by my understanding, the J-10C is the best - if not the only viable option.
And based on past experience and also rumours, I expect a first order of about 36 aircraft for 2 Squadrons but overall I expect the purchase of more than 80-85 if not more.
Anyway, this is exciting news for the PAF. We are going to see more interoperability with the PLAAF and more advanced munitions going to the PAF. There are also new technologies in the J-10C that the PAF will have the opportunity to utilise for the first time in its fleet.