If you can get some good bamboo, use it for the backing. It WILL mater which side of that board you glue it to. Your 4th pic shows the board with few knots on its face. Glue the boo ( or whatever backing you have ) to that side. What this does is it allows you to remove most of the wood with the knots on the opposite side as you tiller it down. I would go for nothing over 40 pounds. Make the bow 2 inches wide at the fades and a pyramid would be best design. I would put my money on this bow coming through for you if you get a good boo backing. Hickory would work to, but the back needs to be PERFECT. Crowned back, flat belly, and if you can deflex the bow a bit while you glue on the backing, maybe 2 to 3 inches, that would be best. You can also glue on siyahs for recurves and get a longer draw out of it without over stressing the wood to much. Go for a bendy handle.