Would not it be better to absorb Chinese tech first that we haven't even touched yet before asking others, Tech comes from the same source it is the type of components and quality that matter and depends on human mind to improve it thus even Chinese tech could be improved greatly and efficiently the only thing lacking is Funds. Lastly so far F-16s, F-15s, T-50 are all from same source US I have yet to witness S. Koreans indigenous technologies making their way to an Advance Aircraft or the current inventory, KF-X is a long shot it might get cancelled in favor of F-35 that's the way it is or else US is heavy influenced upon them all spares or modernization of future F-16s, F-15s or even T-50/FA-50 could be suspended, that's why never put your eggs in same basket S. Koreans did, I am skeptical of KAI KF-X, it may never materialize or again US might assist them.