I guess I'll chime in since you haven't gotten any replies yet. Maybe someone else could give you a better answer though.
I ran into the same problem two years ago finding stock wide enough. Fellow knifemaker Gary Bradburn was kind enough to point me toward a leaf spring manufacturer in Wichita Kansas by the name of Atlas Spring & Axle. Their phone # is 1-800-362-3175. They don't always have the wide stuff in stock, but carry up to 4" wide. Now then, I want to caution you. I got my bar in mid 2003, and I got a bad piece. The steel was very inconsistent. Call them directly and talk to Ron Allee, and ask whether they've gotten in a new batch since then. If they're still using the same pile of that size they had in 2003, I would personally look elsewhere just to be sure. If they've gotten in a new batch since then, you should be OK, and they are generally happy to accomodate knife makers. I know you were looking for a local source, so good luck. But my bar (2 1/4" wide) only cost like $25 or so with shipping back then. Shipping was more than the steel.
That said, something 2 feet long and 3 inches wide sounds mighty interesting! I'd love to hear what you're making, and what you plan to use it for.
also i have a pretty small budget so i'd have to take that into account