Which specific surahs and verses are recited in the two rak'ahs of the Fajr Sunnah prayer? And are the verses mentioned from Surat Al-Baqarah and Surat Al Imran part of the Sunnah? And how can the different narrations in the hadith be reconciled?

Shaykh Al-Albani said: The Prophet, peace and blessings be upon him, used to recite very lightly in the Sunnah (voluntary prayer) of Fajr, to the extent that Aisha would ask if he had recited Umm Al-Kitab (Surah Al-Fatihah) in it.

Sometimes, in the first rak'ah, he would recite: (SAY, "WE BELIEVE IN ALLAH") to the end of the verse, and in the other: (SAY, "O PEOPLE OF THE SCRIPTURE, COME TO A WORD THAT IS EQUAL") to the end of the verse, or (AND WHEN JESUS PERCEIVED FROM THEM DISBELIEF) to the end of the verse.

And sometimes he would recite "Qul Ya Ayyuhal Kafirun" (Say, O disbelievers) in the first, and "Qul Huwa Allahu Ahad" (Say, He is Allah, [who is] One) in the other.

It is also reported that in the first rak'ah he recited: (SAY, "WE HAVE BELIEVED IN ALLAH AND IN WHAT WAS REVEALED TO US"), and in the other: (OUR LORD, WE HAVE BELIEVED IN WHAT YOU REVEALED AND HAVE FOLLOWED THE MESSENGER, SO REGISTER US AMONG THE WITNESSES) or (INDEED, WE HAVE SENT YOU WITH THE TRUTH AS A BRINGER OF GOOD TIDINGS AND A WARNER. AND YOU WILL NOT BE ASKED ABOUT THE COMPANIONS OF HELLFIRE).

The matter is broad, so whoever recites any of these verses has indeed followed the Sunnah.