Would some of Polands westernised Migs be capable of launching them?
No, these are likely fully NATO and adapters from Slovak/Polish/Bulgarian MIGs were used.
I heard the Slovakian MiG-29 might have been modified to fire HARMS; there were also rumors of a ground-based system, but the integration with the targeting computer seemed questionable.
My thoughts also, that some of the planes given to Ukraine may have been modified to be compatible with NATO standard bus and weapons.