One of the best ways to gear up your characters in WoW Cataclysm Classic is to use Justice Points to purchase gear after completing PvE content.
WoW Cataclysm Classic Where is the Justice Points vendor in Orgrimmar
Justice Points are earned by defeating dungeon bosses in Cataclysm. They were first introduced as a way to earn gear during the Wrath of the Lich King expansion, and remain in the game as Classic WoW transitions into a new era.
Gear that you can purchase with Justice Points in Cataclysm Classic equates to many rare (blue) quality dungeon drops and can cost between 950 and 2200 Justice Points. This means that you will have to do a fair amount of dungeon farming to add these pieces to your Cataclysm character's gear.
Here you will find all Justice Points quartermasters and vendors in WoW Cataclysm Classic.