Suzuki and Etec are definately directly NMEA capable. Honda is running a version of NMEA 2000, but not sure if it will interface with RayMarine--especially the C series. (Yamaha and Merc also have varients, but not the full NMEA protocol, and thus at this point I do not believe that they can be read).
See:http://www.jackrabbitmarine.com/files/NMEA2K_Network_Design_v2.pdf This is one of the best summaries of the NMEA protocol, but may be slightly out of date. There is a standard NMEA backbone connector to Sea Talk for the "E" series.