Indeed, one at each end of the aircraft.
further more (in very simplistic terms!) an existing automatically deployed ELT unit could be fitted with an "SD card" which is fed data from the FD/CVR pair in real time. the unit would be charged, and the data fed to it, via an inductive loop, obviating physical electrical connections to the aircraft's systems.
Assuming the ELT was found and recovered the SD card could be read. I suspect a high capacity SD card would probably hold months worth of voice and flight data!