Not on XBox but if it is like PC and PS4 go to Reapers March, Craglorn, Deshaan, Grahtwood and Stormhaven. If you check all of the guild traders in the main city in those 5 zones you will have the best chance at finding whatever gear you want.
PUG Life - the true test of your skill
18 characters, 17 max level, at least 1 Stam and 1 Mag of every class, 1 of every race and 1200+ CP
Tanked to Undaunted 9+ Mag and Stam of every class using Group Finder for 90+% of the Vet Dungeon runs