If you are interest in growing apples in Texas, an important consideration is always the type of rootstock that your tree will have. Some rootstocks are hardier than others. Some do better in our clay soils. Rootstock also dictates how large your tree will eventually become.
Read the following posting by Kuffel Creek about rootstocks - Rootstock Article.
He posits that rootstocks will underperform in size in a hot climate like California -- or by extension, Texas. Consequently, he contends that an M111 that should grow to 12 feet, will only grow to 8 to 10 feet in a hot climate. That is a good size for a suburban yard.