You might try Sony. I bought one on line from them about 18 months ago. I had to wait a while IIRC the phone rep told me they waited until they had a certain number of orders built up and ran a production run of them on one of their flexible assembly lines. This could be BS coming from a CSR after all but I have known other companies to do the same with other products with low demand but that all of the tooling has been long paid for. It has both a coax and toslink for maximum flexibility. I have mine laying in the back of my cabinet hooked to the switched outlet of my reciever (I knew I would find a use for them one day).
I tried to add the MOD-RF1 to my cart and kept getting timeouts. You might need to call them on something like this to accurate info though.