yea, theres no such thing as a fw moray. It could survive in FW when its young, but will need to be moved gradually to full strength SW as it gets older.
While we are on the topic so do Monos and Scats so that is why they make good tankmates. IMO, SW Morays are much more exotic and attractive so if I were you I would just set up a sw tank and get a sw moray like a Zebra, Snowflake (Echidna nebulosa-true sw one), Chainlink, or some other one !