The TSFL guide says you can have any low fat or low carb dressing that has 6gms or less of carbs per 2T serving. Obviously, the lower you go, the better off you will be. And calories are important just to watch.
If you like italian, Ken's Light Northern Italian has only 1 carb gram per 2T serving!! It is awesome! And if you like ranch, HIdden Valley only has 2 gms per serving. Also, I found a low-fat one I prefer called Naturally Fresh Low Fat Ranch (in the salad bag section, with Marie's) that only has 2 gms of carbs, and only 80 cal per 2T serving ~
Just some ideas
p/s ~ where in texas are you from? there are some of us in the dfw area that are going to try to get together for a l&g next month if you're interested~