would like to say my twink Joanrambo (lvl 19 warrior on sunstrider) is considerd the best on my server , my highest 1h crit with shadow fang/crusader is 309 heroic strike and i still have 1800+ hp my stats are not fixed on stamina only and i have a few extra bits of gear depending on what the horde are spewing at us. trust me when i say 1h/shield is the way forward i have night reaver/crusader and smites/25 agilty and i do alot more dmg with shadowfang over all throughout the battle ground...well rattled on enough cya  heresa link to my toon.....http://eu.wowarmory.com/character-sheet.xml?r=Sunstrider&n=Joanrambo

If you are serious about 19 mages, make a horde... the deal is stack fire damage, spec frost, freeze and then melt face

Heres my recomeneded build.

Lucky Fishing Hat, +8 spell damage
Scout's Medallion
Talbar Mantle
Feyscale Cloak +70 armor
Inferno Robe +150 health (Yes its a 35+ item)
Crystaline Cuffs +9 Stamina
Serpent Gloves +20 Fire Damage
Keller's Girdle
Darkweave Breeches +35 Spell damage / +20 stamina
Nat Pagle's Extreme Anglin Boots Boar's Speed
Lavishly Jeweled Ring
Advisor's Ring
Insignia of the Horde
Arena Grand Master

.... of Firey Wrath (1h Sword or dagger)+30 Spell Damage
Pulsating Hydra Heart
Banshee Rod of the Sun

that is all, with that though, your looking at roughly +150 Firedamage.