You won't need an earth knight.
You have a wind knight, so you won't need to JS I guess. Then i'd go for seer (becouse you can get a good cape, and I think that seer js *de-seals*?).
But yes, you know what they say, if you can't pick one.. then go for random! o3o.
Consider wits for better seals, seers for faster ones (+supper effectivenes in CP! :D).