Yes, the men are Moses and Elijah. When you have a question like this, remember that the main Fisheaters site has a search engine. Enter "Transfiguration" et voila:
"Recall the prophecy of Daniel:
I beheld, therefore, in the vision of the night, and lo, one like the Son of man came with the clouds of heaven, and he came even to the ancient of days: and they presented him before him. And he gave him power, and glory, and a kingdom: and all peoples, tribes, and tongues shall serve him: his power is an everlasting power that shall not be taken away: and his kingdom that shall not be destroyed.
Today we recall when Moses, representing the Law, and Elias (Elijah), representing the Prophets -- two men who had special visions of God -- appear with Jesus on on Mt. Tabor (Matthew 17, Mark 9, Luke 9). There the Apostles see the Divine Uncreated Light shine forth from Our Lord, Who'd told them previously that He must die and be resurrected.
And after six days Jesus taketh unto him Peter and James, and John his brother, and bringeth them up into a high mountain apart: And he was transfigured before them. And his face did shine as the sun: and his garments became white as snow. And behold there appeared to them Moses and Elias talking with him.
And Peter answering, said to Jesus: Lord, it is good for us to be here: if thou wilt, let us make here three tabernacles, one for thee, and one for Moses, and one for Elias.
And as he was yet speaking, behold a bright cloud overshadowed them. And lo, a voice out of the cloud, saying: This is my beloved Son, in whom I am well pleased: hear ye him.
And the disciples hearing, fell upon their face, and were very much afraid. And Jesus came and touched them: and said to them, Arise, and fear not. And they lifting up their eyes saw no one but only Jesus. And as they came down from the mountain, Jesus charged them, saying: Tell the vision to no man, till the Son of man be risen from the dead.
Christ, as the Temple Who would be raised up three days after 'it' was torn down, shows that He is, indeed, He in Whom the glory dwells. As the Creed says, "Deum de Deo, Lumen de lumine, Deum verum de Deo vero" (God from God, Light from Light, true God of true God).
Of significance to this Feast is what it reveals about true Judaism. From the Catholic Encyclopedia:
False Judaism had rejected the Messias, and now true Judaism, represented by Moses and Elias, the Law and the Prophets, recognized and adored Him, while for the second time God the Father proclaimed Him His only-begotten and well-loved Son.
St. John Chrysostom writes more about the appearance of Moses and Elias in his Homilies on the Gospel of Matthew:"
To read the rest, including what St. John Chrysostom wrote, go tohttp://www.fisheaters.com/customstimeafterpentecost5.html