It's not a native but Rosemary makes an excellent box hedge to the height you want. It's hardy. Tolerant of sandy soil and extreme heat and drought tolerant. The purple flowers are stunning, it's an excellent herb and it's quick growing.
They have been used extensively in my area as part of the street scape.
On a slight off topic (bless Trees ;) , I'm surprised how the grocery stores still sell one sprig of Rosemary when you can pick it free at the centre!
