Outside of the Dark/Light Side vendor I have not seen a single piece of gear that requires Dark/Light alignment that isn't a Relic or Lightsaber (Red, Green or Blue Crystal)
Torhead, DarthHater and Swtor-Spy all have entire sets of alignment gear data mined but where are these items? I have not seen a single piece drop, not a single piece on GTN and not a single piece on another person. Are they one of those things that were scrapped from beta just like heavy/medium social armors?
EDIT: Both Lightside and Darkside vendors has both a pair of boots and gloves (Voidwalker for example) with matching Chest,Pants, Bracers,Head and Belt, that are all data mined but nowhere to be found ingame.