the better your tiller the shorter you can go,,,rawhide backing on the shorter board bows is good,, try the 60 inch and see how you do,,, or like it,, then you can always experiment to the extreme,,red oak is good,, but I think a little more inconsistent than a stave or hickory,, I have made some nice bows with red oak, but if I want to push the limit,, I dont think it is the best choice,,, well designed it shoots very well,,