Hey, if it's working for you, I don't think you'll get any complaints here.
If you don't have other wood types available, I'd definitely recommend ebay. If you pull up the site and just run a search for 'bow staves', there are usually a couples pages of staves available. There is the downside that once you add shipping, you'll usually be around $50 - $70 for a stave, so a little pricey. But you can get a nice stave that's all set to go. Not all, but may of the staves I've used were ebay purchases.
All your bows look great. I'd be curious to see what you could do with a nice piece of osage.