Why not try an e-mail to the Defence Attaché in the British Embassy in Warsaw. He may have details of veterans, but will certainly have links to the Polish Air Force, who have all the records. I hope I'm wrong, but I don't think there are any ex Spitfire pilots left in Warsaw - many of those who returned after the war were persecuted by the Russians, and those who survived or avoided that have passed on anyway.
Good luck.