Zradix,
You're right, I mean if you go wide enough and long enough anything will make a bow.
But who wants to shoot a 6" wide, 80" long bow made from radiata pine? Not me.
I'venot used osage personally, but 1000's of people cant be wrong. Ipe I have used and is also excellent. there are other hardwoods that are good, but if you don't already have materials, why settle for less. Get the best. Get ipe or osage.
Tenbrook will sell you bamboo and Ipe together, and they're reputed to be of very high quality. Think about it.