Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Fireproofed Chestguard Compares
Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Fireproofed Chestguard suits Assassination, Outlaw and Subtlety Rogue; Brewmaster, Mistweaver and Windwalker Monk; Balance, Feral, Guardian and Restoration Druid; Havoc, Vengeance and Devourer Demon Hunter.
Transmog Sets
Fireproofed Chestguard is part of the transmog set Vestments of the Red Crane (Monk only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 90419 (90414 to 90424) were usually added in the same batch as Fireproofed Chestguard: the same quest line, zone, vendor or reward set.