There are a few in Houston scattered around the core of the city. However if you come to Austin there are a few neighborhoods that have mid century modern homes. The most prolific Mid Century Modern architect in Austin was A.D. Stenger. He built several homes n the Zilker/Barton Hills area and there are still a few of his homes in the Westlake/Rollingwood area. Sadly many of the homes have been "updated" and some of their classic features were destroyed, however a few remain that are true to his artistic vision. You can Google him to see some of his work. He was also known as the Father of the Atomic Ranch home. There is a website called Living Modern.com and there is a string in the forums section about A.D. Stenger and you can see some photos of his work here:
If you come to Austin I would be happy to show you these homes. They don't come up for sale very often and they usually sell quickly due to his cult following .
Austin Home Girls Realty