My favorite is Southside Market. They sell them in HEB. I unfortunately don't have one near me but you can order online here:
southsidemarket.com
I make my own mostly, though. Another I will occasionally use is Zummo's brand andouille which is out of Beaumont, Tx. It turns up at my local grocery store.

Iconic Sausages from Elgin, Texas | Southside Market & Barbeque
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I make my own mostly, though. Another I will occasionally use is Zummo's brand andouille which is out of Beaumont, Tx. It turns up at my local grocery store.