About who supporting the PKK? The West, right? Only when it's the Germans, the French, the British or the Americans supporting them it's a problem and Turkey won't buy their SAMs, but when it's the Russians, or the Arabs everyone in the AKP is closing their eyes and everything is cool.
What about Russia's never ending support for the PKK ever since it's foundation? The PKK was founded as a marxist- leninist organization and was supported by the USSR and the Warsaw pact for many years. Just look at Russia's role in Syria and how Assad and them are together with the PYD every time it's against Turkey. A lot of PKK's weaponry is russian- made etc.
Instead of investing billions in Russian equipment that we will have to wait years for and which will take lot's of time to integrate we should better invest in our own capabilities and try to develop our own system. We should better look for a partnership with neutral and friendly countries like Pakistan, Japan, South Korea, Indonesia, Malaysia and why not even Brazil.