Actually! I have a 29 twinky you may have seen run'n 'round name Hayl, and he is a Mage.
I can tell you first hand, you dont need to stack stam at all! mana shield, blink, and frost nova go a long way in protecting your tender ass.
All classes but 2 are very, very easy to kill as a mage, and this includes rogues. The two difficult classes are Hunters and warlocks. I'd love to discuss strategies vs. them with you some time, i've found some methods that work rather well.
But, back to the primary theme of this post, GEAR!
HELM:
first, BE AN ENGINEER. the best helm you can get is Spell Power Goggles in my opinion. That stacked with a Libram of Focus is +29 spell damage (all types! so sexy.) Plus the bombs you'll make just leveling up to 215 engineering will come in handy in the BG's
GLOVES:
next, there are the hotshot pilots gloves. SUPER RARE. good luck to hold you over, consider nabbing Ressilient Handgrips or the Vital Handwraps of Fiery/frozen/arcane Wrath.
BELT:
you have the Ghamoo-ra's Bind selected, this would work, you would get +4 int over the Defilers pvp belt reward, but at the cost of 3 spell damage, some armor, and stamina. I will admit, running out of mana sucks so the more int the better but..
BOOTS:
Definitely use the Defilers PVP reward you have listed. Speed is king, and they got good spell damage to boot.
CLOAK:
I also went with Conjurer's Cloak of Fiery/arcane/frozen Wrath - consider getting each type if - pick them up when you see them, you may change your mind on which school of magic you use given the situation you are in.
WEAPON:
Advisor's Gnarled Staff - Very good item, but for now ive been using the Acrobatic Staff of Fiery/Frozen/Arcane Wrath for the extra spell damage. I wrote simple macros such as /cast Fireball <next line> /equip Acrobatic Staff of Fiery Wrath - that will equip the item as i cast the spell of a given school (frost bolt and arcane missiles) and even if combat, the global cooldown resolves itself within the cast of the spell, making it a non-issue. I do use the Advisors staff for mana regen between fights often or if i get into a situation where the stamina, int, and mana regen wil lcome in handy (flag running, certain class fights, etc).
WEAPON2: --sorry WoWhead went down for maintenance! no linkys here--
you can mainhand a lower'ish level dagger of arcane/fiery/frozen or a stam or int one handed weapon and the pair it with the +10 spell damage offhand quest reward item from a Scarlet monastary library book retrieval quest. This would give a total of +40 spell damage from your weapon slots, plus a lil int, sta, or possibly another +6 spell damage in a specific school from the one hand weapon choice. There is a one handed sword, random lvl 29 to equip world BOE drop that is SUPER rare, that has +6 spi, +5 int on it...ive been look'n, have yet to see it.
CHEST: --sorry WoWhead went down for maintenance! no linkys here--
consider Death Speaker Robes from razor fen Kraul 2nd boss, Deathspeaker Jarba, (he also drops Deathspeaker mantle the best shoulder slot item with 7 int and 9 spell damage) or the Robes of Arugal for the 12 spell damage and stats.
i recommend every day you log in, stroll over the the AH, and type "fiery" (and arcane, and frozen) and scroll to thru the results, pick up the items that are in the 20's. it can take a while for hte specific one you want to drop to be there ;(
anyway hope some of this helps, lets talk in game sometime about it all (including talent choices). And check out Hayl on the armory if you want.