Updating: Ray230 to Ray260

Besides the cabling issues I face with a dual helm instillation, what connectivity issues should I be prepare for in this process? Current MFDs and auto pilot on my Sealine F43/5 motoryacht are (circa 2004) a Pathfinder RL80s and auto pilot. Although I have yet found the connection block, all appears to be NMEA 0183/Seatalk. Both Nmea0183 and Seatalk plugs are in use.

Please advise.

Thank you.
FPCJR / Siboney / San Francisco Bay