The Hot Pepper said:
Make your own. I know it's a combo of something like cayenne, garlic, onion, salt, and a couple other things but the cayenne is key! Phil???????
When I say Zat's instead of Old Bay, I'm just talking about for boiling seafood.
http://www.amazon.com/Zatarains-Extra-Spicy-Crawfish-Shrimp/dp/B006UCUAN4/ref=sr_1_6?ie=UTF8&qid=1419722504&sr=8-6&keywords=Zatarain%27s+crab+boil
Add a whole jar of this to your 80 qt boiling pot for a treat.... Zat's is great, but I'm not that brand loyal, and there are plenty of other great alternatives... just not Old Bay.
Tony Chachere's creole seasoning is great for gumbo. You probably don't wanna use Zat's for gumbo..... only for boiling seafood. (Pronounced "Sash-er-ree)
http://www.amazon.com/Tony-Chacheres-Original-Creole-Seasoning/dp/B00D1G7LZM/ref=sr_1_1?ie=UTF8&qid=1419722711&sr=8-1&keywords=Tony+Chachere%27s
Or you could make your own like Pookie said. Sounds like you have the basic essentials in there. Even try substituting your favorite pepper powder for cayenne... with the understanding that as the pepper changes, the flavor changes with it, right?
For my own cooking, I just use kosher salt and pepper and add cayenne as needed for spice. Sometimes I add my homemade smoked scorpion mutt powder, and I usually get in trouble for it... hehehe. As long as you're cooking with the trinity and fresh chopped garlic, salt, pepper, and cayenne are all you need. Spice is important for cajun dishes, but it's mostly about flavor. Flavor is king.
BTW.... it's extremely difficult to make a "diet" cajun dish. They're usually loaded with fats and salt, Kiss your good cholesterol levels goodbye! And yes, I am on Crestor... AND blood pressure medicine. On second thought, ignore all of my advice. lol