You might want to try an Elm sapling (1 1/2"-2 1/2" dia) they are easier to work with and can handle the high crowned back. Elm also handles high stress designs and heat treating very well, but the belly has to be flat. I have a 58" ntn 55# @ 26" sapling D bow with slightly flipped tips I just finished, it's from a small 1 1/8" diameter (@ the handle) American Elm. And a 64" ntn 65# @ 26" D bow from a 1 1/4" Elm sapling. Neither one has taken any set. The best part is you dont't have to do any splitting. It's my favorite wood to work with, I say give it try.
Cheers,
Thunder
-I'll try to post picks this evening