What is the best commercial mild low/no salt cajun seasoning from Louisiana?

I'm afraid you won't have much luck with the pre mixed stuff. By nature these blends are high in salt, usually the first ingredient. You really have to make your own to get a low salt blend. Try the mix on Nola cuisine.com and adjust the blend to your taste. You may not be able to get a pre mixed but how about getting some cool jars and labels and ping out your own low salt blend to your friends?