The Vest, Gloves, Boots and Gear Perk system is not available in Zombies. Instead, receive a permanent boost (throughout a Mission, unless you fully die) to various in-game attributes by finding (or crafting) a Perk-a-Cola:
Aiming down sight moves to enemy critical location. Increase enemy critical damage.
Obscured enemies, chests, resources, and item drops are more easily spotted.
Every bullet you fire has a small chance to apply a random Ammo Mod effect.
Increases maximum health.
Diving to prone triggers an explosion. The explosion increases the higher you fall. Immunity from fall damage while diving. Immunity from area-of-effect damage from weapons you are using.
Reduce the health regeneration delay time by 50%. Reduce the time it takes to revive an ally by 50%.
Drink to reload and replate armor faster.
Increases run and sprint speed.
On death, you create a tombstone stash at that location, containing your backpack inventory in the next game.
COD MW3 Bot Lobby, Boosting, Accounts
Perk-a-Cola Machines: This allows you to purchase a beverage that increases your prowess in a variety of ways (see above).