CISPR16-1-2 is the basic guidance for ISNs. Note the frequency curves for max and min Z; that is the characteristics of your particular ISN is dependent on the data generated by your calibration contractor or however you get your calibration plots.
Some generic EMC standards have both normative and 'suggested' ISN connections; and some do not. In any case, I have not seen 'banana' connectors for the AWM output on anything made in last 10 or 15 years.
Power wiring out of the ISN and into the UUT, at frequencies intended for conducted emissions measurements of appliances, should be representative of the intended end-use.
Typically, mains impedance of the in-line components are much higher than that added by conductors for appliances and IT equipment. Power into the ISN is generally assumed to be per a narrow range of Z.