I can virtually clone any item, so not sure...unless there's something I don't have yet? One good possibility is a Yellow Shard if you have any; I'm sure I'll come across one sooner or later, but they are randomly found like the Red, Blue, and Green ones in caves (where I found those three), and might activate AR on W2 only briefly to clone those when the time comes, with other cloning in my Black game. Otherwise, I'm trying to think of an item that I haven't picked up yet; I can't think of one.
The Everstones are all in my Black game, but I am thinking of importing more Pokémon into W2 that are Black-exclusive (and in some cases, not found), so I can transfer Everstones (cloned or otherwise) from there or from Black, later sending the Shard in a similar intergame swap. My question is how many Everstones are you seeking? I could clone 99 Everstones, sure, but I don't think I have room for 99 Junkémon. :D
Speaking of, are there any baby species you'd like that aren't in Unova? If it's in my three boxes of babies, I can send one with the Everstone. I'm literally trying to give some away. :)