With Suzaku scrap
Double Attack +1~2
Crit. hit damage +1~3
you could always get zahaks mail which is basically the same thing w/o double attack
Pretty sure Zahak's is critical hit rate. @OP you could buy a grim+1 before you managed to hit perfect augments unless you're *really* lucky (gil wise).
Edit: In regard to the differences in body piece in peoples sets is generally for when attack is capped or not. Grim(+1) was generally swapped out for Z.Mail (or maybe twilight?) when attack was capped. But with the new voidwatch tiers even w/ drinks i doubt attack is easy to cap although i have never been DD yet so..