The tightly woven polyester that's commonly used for kayak skins is very strong and abrasion resistant. The type of knit fabrics you're talking about are junk and would never stand up to the stress and wear of kayaking. If you want to try something that's got some stretch, you could use Dynel. It's very abrasion resistant and is commonly used as an abrasion layer on the outside of hard shell kayaks and paddle edges. I've used it for that, but have no idea how well it will work when sewn. John R. Sweet sells it. Perhaps you should order a yard and test it?