According to Wowwiki, both the tribal and Dragonscale could work. If you're looking for the better for Shaman, go for Dragonscale; the Netherstrike set is a caster set (although it is attack-oriented, not healing oriented; +damage, not +healing). Fill in the other pieces with tailoring BoE pieces or regular mail drops.
http://www.wowwiki.com/Leatherworking