Cross-fade

I know this subject has been beaten to death a few times, but after searching through the old messages I have not found an answer.

I have a 200 and 300 SOny ES CD changers with seperate TOSLink outputs to my receiver (soon to be done via DXS). Both blayers are connected to slink-e via seperate port.

I would like to be able to do cross fades in the same manner as I could when the 2 players where connected in a master slave relationship and via analog connections.

I don't particularly want to build one. Can someone recommend a suitable mixer that would allow cross fading between the two players as CDJ switches between them.

Thanks