Don't you mean minnow trap? Perch traps are illegal in fresh water in Texas.
Because in the tpwd regulations the term "perch trap" refers to saltwater piggy perch traps. We say perch and mean sunfish, which are legal to trap in fresh water.
Academy has some. The better quality ones are online, seen some on eBay. Stay within the 1"x3" regulation for the opening wherever you find one.