Braid.
I troll braid. Less friction in the water; gets down deeper than mono. Don't know if it's right, but it's what I do. I typically use about 15-20' of mono leader. Absorbs some at hook up and from the head shakes and gives a better hand hold than braid when leadering boatside to land the catch.Not familiar with your set up so can't give an opinion on that.
All braid is acceptable but needless expense. As you said, you don't put a mile of line out so why pay for 500 yards of braid when you can put half or less on. Keep in mind, it also depend on what you are fishing for and how much of a run you expect out of a fish.
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