AK can (as currently implemented) be completed with a party of 4 using:
lv44 Grand Company Weapon (you unlock lv50 by clearing this dungeon)
lv45/50 AF armor (head / body / hands / legs /feet)
lv40~50 waist / accessories.

Any problems you have with DPS come from either a lack of understanding of the job you're playing, or a lack of understanding of fight mechanics leading to a death. Things like : Paladin should be using Sword Oath the entire fight, Warrior should not be using defiance. Mages should be putting up instat-DOTs while moving to avoid the sludge (Aero and the like). White Mage should probably use Medica-II so they can focus more on DPS rather than single-target healing (since the wall basic attacks are un-tankable), while Sch's can use AoE dmg shields.