No, I stopped looking for now. Since it has been a little warmer, the bike is running well. I don't have much in the way of mods that would necessitate a different (better) needle. K&N filter, no PAV, drilled bazooka. I don't have the carb dialed in quite yet, but since it's running a little rich, I'm not in a big hurry.
I saw the different jets and needles - very encouraging. I'll probably go further with it this Summer.