Tough to go wrong in that area. Randol's, Mulate's, Enola's. Maybe a touch touristy but the atmosphere is neat. Is Whisky River Landing still there, or did the floods get it? If you have the means to cook or store refrigerated food get some boudin (seafood boudin is my favorite). Just ask the locals where they shop. Three people, four answers but that's part of the fun.
Sounds like your timing is coming up on the Breaux Bridge Crawfish Festival. DON'T MISS IT! Cheap crawfish, cheaper beer, and awesome music.
Have fun! That is a great part of the country to road trip.
I have been to Cafe des Amis three times. The first time I had BBQ Shrimp and some kind of fish (I don't remember). It was all excellent The second time I went to the Zydeco Breakfast and had Eggs des Amis. Again, excellent. The last time, in January, I ordered BBQ Shrimp, but that was not what I was served. Etouffee, maybe? It was very good, but I did not appreciate the switch.