^^^I think Data "dying" is gibberish. They just build a new copy. Data is effectively immortal, which makes him wanting to be human insane. As in sucidal, anyhow.
No, they can't make a copy. Even if they could make a copy, it still wouldn't be Data, even if the programming of the new android is exactly the same as Data. It's be a copy, NOT Data. But since you know, the programming of this new copy wouldn't even be the same, you wouldn't even have that.