You can buy SAM splints here:

http://www.firstaidsuppliesonline.com/nav.pl?search=Sam+Splint -

along with many sizes and styles of pre-made FAKs and lots of the supplies for "build your own."

That is often a problem I find - there are lots of good ideas and handy things....but where do you BUY them? We have the usual Walmart and one national-chain sporting goods store, but there isn't much there. I have bought some things on Amazon, but had mixed success; loved some of it, but others the quality and price were fine, but shipping was ridiculous.