Quick fix for a bit of a problem.
Happens every time - Blizzard has released a hotfix for Mists of Pandaria -- as outlined by Perculia over on Wowhead -- removing the Golden Lotus faction requirement to purchase Justice gear. The idea, Blizzard said, is to let people gain item level 450 gear more easily, so the Dungeon Finder Heroic dungeons are easier to get to.
To get Justice gear, Rushin the Fox in Shando-Pan Garrison and Lo Pin in Niuzao Temple have them in Townlong Steppes, the Sages in Horde or Alliance Shrines, Jaluu the Generous outside of Mogu'Shan Palace, or Ambersmith Zikk in Klaxxivess. Depending on your faction, you will need to visit any one of these.
Julian "Mirai" Williams