Simrad Broadband 3G spec claims as below:-
"SimNet or NMEA 0183 with cable kit into display".
To me this means the Raymarine should be capable of presenting the radar overlay provided one goes into the NMEA port on the Raymarine set.
I suggest you ask both Raymarine and Simrad for their advice. I have always found them both helpful.
Perhaps Sailfast1 would enlighten us further as to what engineering is necessary to make it work?
See link:-
http://www.simrad-yachting.com/Products/Marine-Radars/Broadband-3G-Radar/Specifications/