Hi. I am very ignorant and so have no clue what EFM encoding is but are you talkin about this?
If so, I think I've seen somewhere on this forum about the LiteOn drive capable of this function. Sorry, I might be wrong...
As for the dual layer burners, they won't be coming out for a while. I've heard that they will be released at the end of this year or early next year. But who knows.