Tank Artifact Armor

[PK_THUNER]

Oh but is the artifact armor the highest for level 70?

No if I remember the AF gear is 290 the lv 70 dungeons drop 300 and tomestones of varity give 310 and ex Susano drop 320 wep and ex lakshmi drop 320 accessories.

[VenKitsune]

Lvl 70 jobs quest gets you...
Your last Skill
Artifact Weapon, Artifact Head, Artifact Body, Artifact Hands, Artifact Legs and Artifact Boots. All of these are ilvl 290.
Dungeons Drop ilvl 300 Accessories and left side, and even weapons if you're lucky.
Verity Tomestones allow you to buy ilvl 310 Left side, Right side and weapon. Verity is obtainably from the 3 lvl 70 dungeons.
Susano Extreme Drops ilvl 320 weapons, You get a token for each kill and 10 tokens can be traded in for a weapon if you're unlucky enough that a weapon doesn't drop for you.
Sri Lahkshmi Extreme drops ilvl 320 Accessories, Same deal with tokens as Susano but her accessories are 5 tokens each. She drops ALL accessories.

Honestly the Extreme primals are pretty easy due to being entry level so i would encourge you to give them a try :P