Kronenbourg is available in one-liter "mini-kegs" (a big can), that are handy as "boat-beers". I used to by them by the case in Charleston when I lived in SC. Unfortunately, one case I bought was completely uncarbonated....turned me off to Kronenbourg.
I never could develop a taste for Shiner Bock. A much better one is Paulaner Salvator (pronounced sal-VAH-tor), which may not be available in Texas, although I think I remember seeing it at the Gingerman. It's definitely worth hunting up. Ayinger also makes a good bock. For a great Doppelbock, try Samichlaus (brewed by Hurliman of Switzerland) (again, your best bet is probably the Gingerman). There is a Gingerman in Austin, too.
I got to say that when I lived in Carrollton, TX, I had a BALL when I discovered mini-breweries. Those are great!
I'll make it a point to try the Paulaner Salvatore, and I guess there's a much better chance of seeing the Gingerman in Austin before I see the one in Houston.