When I retired and moved from Maryland to SW Florida in 2007 I used Thomas Sunday to transport my '69 and my '04 Z06 CE. I used Tom because he has been in the business for a long time, he is a Corvette guy (member of Cumberland Valley Corvette Club), and he came highly recommended. He was not the cheapest quote for an enclosed transporter, nor was he the most expensive. But his driver was there on time to pick the cars up and he arrived in Ft Myers when he said he would arrive. The cars were handled very well with NO problems. I don't know whether he will have a specific run from Florida to Texas, but it is worth a call to him. Here is a link to his website.
http://www.sundayautotransport.com/
I have also used Intercity in the past with good results, but when I got my quotes they were a little more expensive than Sunday's quote.
I hope this helps.
Rich