I've never fished for Reds in cajun country, but you'll probably be well served by Clouser Minnows, or maybe some darker flies if the water is murky. Most all of these would be good options http://www.theflyshop.com/fly27.htm
though I would skip the ones with _/0 as the size, as they're intended for surf fishing in the NE. You'll prolly have some people swear to you that "spoon flies" are the ticket for redfish, but they have some problems. They tend to spin like a Tom Brady pass during the cast, doing truly awful things to your leader. They also can be quite noisy when they hit the water, possibly spookying that Red you stealthily sneaked up on. I think you're best off using larger and darker/brighter versions of established bonefish flies.