youll need a 90g tank or larger for a pair of texas cichlids. Ive seen males that are 12" and females that are 10", sexing them is like with most ca cichlids, males will be bigger, fatter, and have an elongated dorsal fin, females are smaller, skinnier, and have a rounded off dorsal fin. Most texas cichlids at about 2-3" cost roughly $3.99 in my city.
However most Texas Cichlids are greyish black, not blue. Could be hybred crossbreed.