Just to give an update on this: We are in contact with NI, the standard cables are not halogen free, there are several costumers interested in halogen free cables, NI is exploring the possibility of manufacturing those provided the quantities requested are large enough.
We are still exploring here, we have already spent several k Euros on cables, replacing them with other cables will mean in the end ~15 k Euros for cables ... this is definitly too much.
Cheers,
flintstone