If you haven't decided on your AIS unit, you should look into SOTDMA (also called AIS B+) . It transmits more frequently and with slightly higher power than AIS B. This is a big technical improvement that can help you be seen by ships.
This Spring I installed a new AIS SOTDMA transceiver made by AMEC (the Widelink B600W with Wi-Fi). It has a built-in hotspot so in addition to NMEA 2000, it also enables me to connect to mobile devices and show AIS targets on my Navionics app (on my phone and iPad). Also, FYI, this was my first experience buying from Milltech Marine, and they were great to deal with. They provided competitive prices, and immediate (competent) tech support when I called. They really know their products.