I think I'd avoid a holesaw. They're pretty brutal, and I've had bad results using them on fiberglass. I'd look at a quality forstner bit. I have a 35mm Milwaukee that is razor sharp and has a great design that slices through anything with ease. Whiteside makes great bits too. I would think the better it slices the better it will do in kevlar because it won't be tearing it up by ripping it like a holesaw. Ripping will raise fuzz, slicing will make closer to clean cuts.

m