I sort of wanted Kakashi to point out to Sasuke that Itachi is gone because he killed him o.O But I think Sasuke purposefully was asking for the impossible because he knows very well that they will never come back. It was sort of meant to be more mocking, I think, than what he actually would expect. The reality of what he was getting at, it seemed, was that nothing would make him stop ever. But Itachi was asked for first because I think Sasuke cared more about Itachi than anyone in the world.
You're right: In order of who he called out for, Sasuke wants the one he killed, Itachi, and he also wants the ones Itachi killed, his parents and clan. (And it doesn't matter if he technically killed Itachi, it was a battle to the death. Both would have died if Madara had not scooped up Sasuke)
But it got me thinking, we know Naruto's motivation lies in the past from his flashbacks, most notably how he views Sakura. But Sasuke also is living in the past, we just don't see any of his inner thoughts. He's calling out for a time with Itachi, his parents and clan, that never in reality existed. The time he was hearkening back to, Sasuke was a kid. But the coup was already underway, and Itachi was already deeply involved in betraying his clan. He's not only wanting something that can never be - bringing his family and clan back - but he want something that never was: parents and a clan that were happy within Konoha, and a brother that was not plotting their imminent deaths.
And what if Sasuke lost his battle to Itachi, would Itachi have killed him then? Would they have strode arm-in-arm off into the sunset. Itachi forced him to become an avenger, a loner, a killer, and now Madara is using that how he will. Itachi never even told Sasuke how to defend himself against Madara, who Itachi obviously didn't trust. So, I think the whole 'I love Itachi now' thing is on shaky ground.
Kakashi could enlighten Sasuke with his own experiences too, his dad died (committed suicide) for his comrades. And Kakashi had to live through it. But...if we focus any more on Sasuke I think we really ought to rename the manga.
Naruto and Sakuras love cannot just save the day anymore; he has killed his heart to the point where he wouldn't know what to do with that love.
Great quote. Sasuke really has killed his heart.