depends on wat type of war buildu have, some farming builds need the extra mana from gladiators while some can sufficiently use the 20 mana pool and require the extra armour from pl8 or knites
A helmet with +1 to the attribute you are using
Gladiator chest
Gladiator lower torso
Gladiator arm or if you use hammer, stonefist gaunlet
Knight/ascalon leg
That is typically known as the best. Against physical damage of course... against magical damage, dragon/wyvern would be better perhaps... but, gladiator pretty much own everyone due to the + energy and offering the same defense as plate.