Recommendations: (respectfully)
1) buy Ipe. I've bought several 2x4x10' boards for about $60 a piece. That's alot of bows in there. Probably close to ten. Obviously there are other choices, but honestly when you consider how little Ipe you need for one bow, it's pretty economical. Especially compared to the fortune they're asking for osage boards. Depending on where you live you might find osage boards relatively cheap on Craigslist. I bought about 15bdft of super clean osage for around $150, it just took a while waiting to find/negotiate the right deal. Think about it: 25 bamboo slats 1.75" x 6' will run you $100, you'll have at least 10-15 good slats. 1 2x4x10' ipe .... $60, which will yield 6 pieces of ipe .5" x 1.5" x 6', and 6 slats to be spliced of .5" x 1.5" x 4'. so we're talking $16/ bow plus glue. That assumes .100" saw kerf.
It's not worth wasting time on crap wood unless you're into experimentation.
2) move on from the purple heart. People have done it, and anything is possible, but if you have to ask the question then the answer is "no" it won't work.