Black walnut makes excellent core lams for your limbs, and I’ve used it on a take down recurve riser that I built for my son. Worked just fine. I did utilize a couple micarta accent stripes to strengthen the riser (just in case) and you could do the same with any material not just micarta/phenolic.
If your talking about building glass bows, get familiar with Binghams website. Everything to get started is located there including plans, and parts lists. Elmont will more than likely respond to you personally regarding any questions you might have if you email him your quesitons about his plans and parts. I think 90% of all bowyers have started with him. Its a one stop shop. Good luck. 🙂