Well,
Raymarine may be out - looks like even if I go with their instruments, and connect them to existing
autopilot head, the Seatalk data will still not get transfered to NMEA output (which is weird, really the messages are the same) - that's what their support told me. Presumably I'd need another conversion box - which I don't want do deal with - I like to keep it simple.
So, I am open to any other instruments. What is a good choice for a set of depth/speed instruments with NMEA output, no frills?