FL and MI I think are the one's that require a non-resident to have a permit from the state they reside in. There are other states that will not allow their own residents to carry on another state's permit.. I don't know if TX is one of those or not...
But, if you are looking for an inexpensive easy, no training required, Non-resident permit that is recognized by TX, go for a PA or WA Non-resident permit. The only restriction is you have to apply in person...so if you ever travel to PA or WA, stop at the local Sheriff's office and plunk down small change. (way cheaper than anyone else's, PA is $20 and WA is $55.25)