That sounds great. I think some minor adjustments are all that's necessary.

Might you consider putting part of Bingowings' idea to use?

VADER: What is thy bidding, my master?

EMPEROR: There is a great disturbance in the Force.

VADER: I have felt it.

EMPEROR: We have a new enemy: Luke Skywalker... He could destroy us.

VADER: Is that possible*? He's just a boy, Obi-Wan can no longer help him.

EMPEROR: The Force is strong with him. The son of Skywalker must not become a Jedi.

VADER: If he could be turned, he would become a powerful ally.

EMPEROR: Yes, yes, he would be a great asset. Can it be done?

VADER: He will join us or die, my master.

*It may be worth hearing if that line makes a difference in the tone of the conversation.

If Vader seems skeptical that Luke could destroy both Sith, it begs the question, "Why was Vader hunting him at all? Personal feelings?(!)"

That would flow nicely into the Cloud City duel where Vader says, "Luke. You can destroy the Emperor. He has foreseen this. It is your destiny. Join me, and we can rule the galaxy as father and son."