I would audit the distributor on whatever requirements apply (that is not directly related to the product realization processes), make sure that they audit their suppliers that are not IATF 16949 certified and supply to you if automotive.You can and should audit them to MAQMSR as most of it is applicable to distributors as well. Just audit or cover what is applicable.
This could not be more wrong!Maqmsr is an IATF / automotive thing. Sine IATF is only applicable to manufacturing I'd stick with ISO.