Not sure what the cable length would be out to a panel but it's probably more than fuse mounted antennas, these cables need to kept as short as possible.
I see that you are in Slovakia, so your regulations maybe different but do you really need a Marker Beacon and DME?
For Marker Beacon, the internal wing tip mounted antenna works well. I had a MB in my original panel and used a copper strip in the wingtip for the antenna.