You can certainly find venture capital in most any part of the country. Here is a list of firms in texas, although I'm not certain they invest in tech or not. http://www.gaebler.com/Texas-venture-capital-firms.htm

You can also try checking with Alexander Muse, who focuses his efforts on Texas based startups for tech.

Hopefully there might be someone with first hand knowledge of securing capital in Texas.

As for Angels, they're angels because they are just wealthy folks willing to help seed a company. They don't necessarily advertise that they are angels, but do so when they hear an idea that they really like. Most of them operate via social circles, and they typically don't take calls straight up for new business pitches. It's just a friendly conversation talking about an idea.