Your new 90 alt, provided you bought the commendations, will already be revered with the Klaxxi if you quest through Dread Wastes and honored with Shado pan if you quest through Townlong. (Unlocked right there 5 pieces of vp gear.) Then start Shieldwall/Dominance dailies to revered (maybe 2 weeks at the most opening 4 more pieces). Now you only have to earn the vp to buy them.
You also can buy 2 ilvl 496 pieces from the AH. They are right now rather expensive but might be worth it. And before you know it you can queue for LFR and start 5.2.