@monami:
What exactly do you mean with ´external tv box´? Is that an external TV tuner for the Medion monitor? If so, if it comes with a full-blown (that is with all RGB signals connected and used) SCART connection you could always connect thru that box.
Have you already bought the monitor? If not, try and find a LCD TV with VGA and SCART connectors. Those should well be capable of displaying your Amiga´s output.
