I've called a half dozen local places, and they all keep recommending eachother
One place was very helpful, but they don't have the adapter either. Another place told me that they just balance lug-centric wheels by the hub anyway. Not sure about that one. Might be worth getting the adapter myself and lending it out to a good shop to do the balancing if their liability allows for it. Otherwise I might have to mail them out to be balanced out of state.