IMO there are a lot of 'ifs' and 'buts' with the Sino-Flankers. The path of least resistance is the J-10CE, and of note, the FC-20 was the originally selected deep-strike/attack fighter of the PAF under AFFDP-2015. The J-10CE will bring us immediate (or easier) integration with one of China's supersonic anti-ship missiles, the SD-10 and whatever long-range AAM they release for export, and other stuff.
My conv's with PAF give me the impression that J-10 does not bring something drastically different than the JF-17. On the other hand, Chinese twins are maintenance intensive.
The more I think about it, the more I'm inclined to believe that the Su-35 is a bargaining chip, for the EF.