Unless you're operating in controlled airspace you don't need to be BRNAV compliant. If you want to be compliant, the GNS430 (even non-WAAS) meets the requirements in AMC20-4 as it's certified to TSO C129a. Your AFM supplement doesn't need to be signed but should relate to an approved modification under which the equipment was installed or otherwise later inspected and certified against which will have shown compliance with indicator requirements and any associated annunciation. BRNav approval can be under a Minor change - an STC is not required, unlike PRNav or LPV.
The KNS 80 is not FM immune so doesn't meet the certification requirements for any 'required' Nav aid unless you have an FM immunity filter installed in the antenna cable.