A field guide to stone artifacts by Hester and turner is probably your best bet. It is a great guide and about the only texas point guide you can obtain for a decent price
I don't know about finding a book specifically about Texas, but Overstreet's newest edition is probably the best you're going to find. I bought mine at Hasting's Books but i can't remember how much I paid.
I'd contacted Dr. Hester recently and he said it would be next year before his newest edition would come out, so the edition on market now would be a good standby. Also his "Digging into South Texas Pre-History" is another good read to get you up to snuff on some of the historical data.