Garden Designer for outside patio/deck

We have a great, bright, sunlit patio (over a two car garage) which has big trees on one side and is very private but open to a driveway and close to neighbors on the other. I would like help designing and implementing a series of large potted trees and plants to create a screen and privacy. Space is basically a large square, 25'X25'. Great seating and eating area but needs the final touch of privacy. Landscape/garden designer recommendations welcome!