First off, I'd go with something EVERGREEN. That way you'd have screening in winter. Then, I'd go with something that makes a small tree and remains more or less vertical in form without getting too wide -- but could be easily sheared if needed.

Are you able to water these and maintain them?

If it were me, I'd consider a holly - vertical grower and a dense grower, but try to get a less spiny one, as there are many hardy to your region... like Yaupon, Ilex cassine, 'East Palatka', 'Spartan', 'Scepter', 'Virginia' (hard to find), Ilex integra, Ilex buergeri, Ilex chinensis, Ilex rotunda, x wandoensis, or Ilex 'Eagleson'. (many of these may be impossible to locate in your region).

Spinier (so, harder to work around), but equally attractive and functional hollies could include 'Savannah', 'Liberty', 'Homefire', 'Fosters', 'Christmas Jewel', 'Mary Nell', 'Oakleaf', 'Oakland', Ilex latifolia, 'Lassie'.

Other plants to consider might be Magnolia virginiana (australis -- evergreen), Ternstroemia gymnanthera (Cleyera), Podocarpus, Viburnum awabuki 'Chindo' (needs reliable moisture), Viburnum 'Pragense' (needs regular pruning to tighten up), Prunus caroliniana 'Bright n Tight', and Osmanthus fragrans (fantastic fragrance), Photinia serrulata (Green Giant), Osmanthus x fortunei (spiny), Distylium racemosum, Laurus nobilis (Bay), Japanese Blueberry Tree (Elaeocarpus decipens), Loquat, one of the smaller Mag. grandifloras such as 'Teddy Bear' or 'Baby Grand', Wax myrtle, Red Bay or Swamp Bay, Quercus phillyreoides, and oh so many other possibilities! You could even mix in some Trachycarpus palms or Sabal palmetto into the lineup.

I'd be tempted to put in, say three Trachycarpus (Windmill palms) equally spaced out at first. Then fill in between them with hollies, osmanthus, or some other broad-leaf evergreen.

I don't know if you are near a large metropolitan area with good nurseries and diverse plant availability or must rely upon Home Depot or Lowes.