I always put the Knight Ring and Leg Ring to Sylvia for utility.
The Magic Ring is must for azel.
I put power ring to Raquesis, until she became Master Knight, but is good with alec or arya.
Shield, Skill and Barrier are very good with anybody, even with Quan or Sidgurd.
Pursuit is good for lex and noish because they don't have that ability, or jamke if you want to make him father.
Elite and Speed are good with anybody too.
But this is my opinion from my experience