I doubt Russia will allow any Russian engines on J10 to PAF let alone Serbia. Either China get WS10 ready for J10 or there won't be any foreign sales.
I reckon it's pretty much agreed there's only one production line for J10A so far, judging from the 1-2 regiments per year production rate. Since J10B is about to replace J10A production, it's more likely for them to convert the existing production line other than build another.
I guess they would stay at current capacity untill the export market becomes available.
PLAN Color?
I have strong confidence AL-31 will be allow on J-10 if Serbia chooses J-10. Of cos, domestic option will be another choice but just like what happen FC-1, CAC prefer Russia engines for export.
Nah, if Serbia aims to join the EU or "embrace the West", then they can't choose J-10 for political reasons - 2nd-hand F-16s or JAS-39 makes more sense, if they got the dough then Eurofighter Typhoon or Rafale.
Haha.. Serbia joins EU? After being bomb by EU and American?? Plus they have such strong ties with Russia. Joining EU will be consider against Russia.
I am 99.9% sure Serbia will not join EU in another 20 years time.