If you specifically must have Tex-Mex and margaritas together, I think your only option is the Seaside Taco Bar, and your food options will be limited to tacos, burritos and chips/salsa. I think they turn out a good product but the bill can quickly become staggering if you get anything other than a few tacos and a drink. They may or may not be open at present;they were dark the last few times I went by. I think the best tacos going in SOWAL can be found, ironically enough, at two non-Mexican entries;that would be fish tacos at the Smiling Fish Cafe and Hurricane's Oyster Bar. I don't think Smiling Fish serves liquor, and Hurricane's serves a horrific wine-based margarita (but both have a good beer selection, especially Hurricane's). If you want to drive a bit, I think a pretty good spot that serves Tex-Mex, margaritas, beer, etc is La Paz in Destin. It is hidden and far, but will satisfy your craving. Hope that helps