From what I can see so far (apply HQ where available):

ARC arm: Crab Bow, crit power+ or accuracy+ materia
head: Rainmaker's Hat, (no DD materia for head)
body: Rainmaker's Tunic, crit power+ materia
hands: Felt Bracers or Fingerless Raptorskin Gloves (white only), STR+ or ATK+ or ACC+ materia
waist: Penance (no materia) or Raptorskin Satchel Belt, enmity- materia
legs: Felt Trousers (red only), STR&DEX+ materia
feet: Cobalt-plated Caligae, (no DD materia for feet)