The Austin area has two of my favorites, 512 Brewery and Real Ale (granted Real Ale isn't really in Austin but they distribute plenty there). 512's Pecan Porter is very popular and I'm a big fan of Real Ale's current seasonal, Coffee Porter. Independence is also down there but I've never had anything they produce.
(Shadowane's comment reminds me that I need to keep track of Jester King in the coming months. Hopefully JK can distribute something up to the DFW area within the year.)
You'll also find Saint Arnold (out of Houston; they've got plenty of distribution throughout Texas). You might be able to find Rahr & Sons (out of Fort Worth) but it could require a search. They've increased distribution in the Austin/San Antonio direction but they've been rebuilding a bit after a roof collapse last year; they've been coming back strong though.
If by luck you find a tap of Franconia somewhere down there (Ginger Man might be the best shot), grab a pint. It is a small brewery in DFW (McKinney). They don't have much presence down there but I've never been disappointed by their beer. Hell, if anything I just want them to get the business

.
I'm sure there's more you can find down in Austin, especially from brewpubs that can only sell their goods in house, but that's outside my immediately pool of knowledge.