Unfortunately, that particular look is a unique design I believe, so you'll need to wait for Mabar/Night Revels to swing around again to grab it again.
If however, you are after just something that's "mostly" white in colour, you could also look at:
Spider Silk Robe, Delera's Vestement, Ironweave Robe, Robe of the Magi, White Dragonscale Robe, Dragontouched Shroud, Robe of Insight, Outfit of the Celestial Guardian, Outfit of the Celestial Avenger, Robe of the Celestial Sage, Order's Garb, and Robe of the Locus.
J1NG