As always for your stats, enchants and gems: Some of them might be better than others depending on your specific gear or talents. Make sure to always sim yourself if you want to know the best combination for your gear.
Agility: Raw damage increase.
Versatility: Increases damage done and reduces damage taken.
Crit: Increases the chance of your spell doing double damage.
Mastery: Increases chaos damage taken and movement speed. Don't play with it, mastery scaling is not good.
The best way to calculate stat priorities for your character is to "sim" your characterFind out how to sim
The only available race for Horde is Blood Elf and for Alliance it is Night Elf.
Chest: Eternal Skirmish
Boots: Eternal Agility
Flask: Spectral Flask of Power
Healing Potion: Spiritual Healing Potion
Armor Kit: Heavy Desolate Armor Kit