What materia and stats I should go for on dark knight?

[DRKoftheAzure]

No you cannot because as I already explained you are directly losing potency by not having enough SkS to hit the 5th GCD of your respective buffs. That is a 100% direct DPS loss due to incorrect melds and ilvl makes no difference to this. In fact, ilvl only aids SkS because it means you have to spend a smaller and smaller amount of your overall stat budget to achieve your desired SkS tier, leaving an overall higher percentage of your stat pool for crit, DH, and Det.

If skill speed does not affect the potency of weaponskills and abilities that do not have DoT effect, then it's not worth stacking skill speed.

EDIT:if I could change my forum user name, I would do it without a second thought just because of boring DRK is with how slow it's recast timers for damage oGCDs, spells, and the fact that DRK only has 1 combo like WAR, and PLD to an extent, and the only tank that has more than 1 combo is GNB...