Yes, you need a WAAS capable GPS, but there are a lot of options. The lowest cost option might be to use the Dynon SV-GPS-2020 GPS Receiver/Antenna with the Becker transponder to gain your ads-b out capability which is the 2020 mandate.

Ads-b in to get weather and traffic is a different kettle of fish. There are many options, but they may not display on your D100.