I realize I didn't give a direct answer in my previous post, and agree with the others that a 6 ft by 18" tank would be best (Height not so important), and even then, you should either be ready with a divider, or another tank for (probably) the male if things so south.
For the fry (if you want to raise a number of them) as they grow, another small 3 tanks or so, to separate the largest from the medium, and smaller fry. Without the separate spaces, the largest, usually kill and eat the smaller. It would also be a good idea to start the separate fry tanks right away, and get a good crop of algae growing in each, with plenty to graze on, the fry are not as apt to kill each other.