I've been doing a bit of research on this lately, and am surprised that I've been unable to find other than the 5ma outlets. I guess the outlets will have to get 5ma GF protection, and live with (or correct) any nuisance tripping. The plus side is that it's a lot easier to reset the GFCI outlet than it is one's heart!
The 30ma GF breaker looks like it might be a good choice for the main breaker, but I don't think GF is required. Being a 30A breaker, you'll need #10 cable to the AC panel with the single pole branch breakers. Per NMEA, the main breaker has to be close to the shore power connector - I think they allow 6' of cable between the connector and the main breaker.
I haven't looked for a 15A 2-pole breaker, which would be nice for a single circuit boat wiring. Using a single GFCI, with the down-stream outlets also protected, would be simplest. Yet, having the full 30A available also has it's advantages - you can use the second 15A circuit for a luxury like a water heater or a 9" South Bend lathe.