Any saw shop can make up the blades for you, so you aren't limited to buying them from a parts house or industrial supplier. They cut them from rolls of blade stock, weld and anneal them, any length you want in any blade width and teeth per inch. Look in your yellow pages for saw shops.
If you can't find one locally, you can order what you want from
Keenedge
http://www.keenedgeatl.com/
They are a small company outside of Atlanta, GA and do good work. Blades aren't very expensive. Call them up, tell them what you have in a saw, tell them what you want to cut, and they will figure out what you need, make it up and ship it to you, usually in one day or so.
Dr. Bob