Buying wood blanks from stabilizers is EXPENSIVE. The vast majority ridiculously over charge. You're far better off buying wood from various sources and sending it to have it stabilized. I would strongly recommend K&G Stabilizing (in AZ) over the other stabilizing outfits. Significantly harder, better stabilizing than most are putting out. Plus their consistency is spot on. You'll pay about $15 per finished pound. It takes them a month, sometimes two. I don't do my own stabilizing but I spend thousands per year on stabilizing services and thousands per year on all sorts of wood and burls. They get 100% of my business and I have used them all. WSSI has similar quality to K&G, although they tend to take a very long time to get wood done.
For the wood itself, Bell Forest Products is a great source. There are a couple sources on here...Check the sale ads. Dbroswoods is one that has great stuff. Ebay is a good source, just be sure you're buying dried wood. Woodbarter.com is terribly addictive and is as good a source as there is.