I have just purchase some Maple and Oak stave from a local lumber sale.

Is maple or Oak a good good for buiding Boo back bows?...........why, why not?
Thanks!

It's not the best choice, but it can be done if the boo is thin enough, otherwise it will crush the belly. Osage, massuranduba, Ipe, yew, or hickory are better candidates for a boo backing.

As bamboobender advises oak and maple really aren't going to hold up to the kind of compression forces that bamboo will exert on belly material.  Osage, ipe, or hickory(in that order) would be better for this application.  Cheers, Matt