Merci Beaucoup to you all for your individual suggestions as well as the valuable references and resources you pointed me to -- this combination is just what we needed!! Laissez Les Bons Temps Rouler!
It is all by "night of the week" down there. You can call the places up (safest) or read Times of Acadiana when you are there (I would still call before getting into the car for a long drive!).
You can see great zydeco or cajun at Randols... but each has its own night---and a different crowd for each. Same for Wranglers in Carencro... even Cowboys in Lafayette.
Sunday Night at Mulates (Breaux Bridge) is one of the great ones--- Al Berard & The Basin Brothers. Great Food, some of the most beautiful cajun music anywhere on the planet, and lots of dancers, too.
If it's the weekend, you've got plenty of choices, for sure. A nice time is to go to Henderson, east of Lafayette, and eat a stellar meal at Pat's... then walk next door to the new, Atchafalya Club. There's usually a great band playing (Geno, Travis Matte, Kevin Naquin, etc.) It's nice, comfortable and huge with plenty of room to work off all that rice and gravy. Then, when the dance is over, you can get the remainder of that 40 oz. dacquiri you got at the Paradise drive-thru out of your car, climb up the levee, and howl at the moon! C'est fun!