Did you try St. Louis Home Fires in Ballwin? Frank has a pretty impressive inventory of sauces and rubs. If he doesn't already have it, he'll probably be able to get it.
Maybe their site has a dealer locator. Or you could email them and ask. Norco turned me on to it and I just order direct. The sampler packs are a good deal (you get to pick), the jars are 5 ounces.