Basically, characters with high Int and/or Cha. Classes of wizard, sorc, rogue, bard, possibly Cleric, Monk, or any class so long as they have a decent Int or Cha.
The Family would expect you to be social, and adept at "wheeling and dealing" so to speak. Forge alliances, build relationships, manoeuvre situations to the Family's best advantage.
these characters would be ideal for the ones being "sent to etaria" to set up a power base. They can go anywhere really, on the proviso they are "gathering information" or possibly allies.