I can at least answer on bending cedar. I bent the coaming lip for my strip-built kayak using cedar and pine. I didn't steam it, but rather just poured hot water over it as I bent it around the form, clamping as I went. I let it cool and dry while clamped and then I undid the clamps and the cedar sprung back some. I clamped it all up again this time brushing epoxy as I clamped and when i undid all the clamps it was strong and has held ever since.

I suggest using a laminated coaming lip just becuase I like the looks of it. You can still put a keyhole out of wood strips or plywood on a laminated coaming.

Good luck on the next project!