Well, there are no truly positive examples for air defense work as of now. While Serbia can be made into a single-use "come bite me" drone Albania, it's hard to come up with imported solutions to somehow defend the country itself. Until recently, Israel counted, but that was achieved via stripping the entire US of both weapons and credibility.
It simultaneously needs fighters and can't make use of them. It simultaneously needs integrated air defenses, but they'll easily crumble and won't help.
Ambush defenses in this geography won't help this time.
And while it's possible to conceptually imagine systems that will work nicely to deter EU aggression, Serbia can't afford them, and no one else can be bothered to produce them.
Chinese private market ... could've produced something suitable, but since all the same solutions are 100% applicable to Taiwan(and probably will be more effective there), I really wonder if it's a good direction to dig in your own.