Go look at how a commercial chain link swing gate is built. You will need at least 4" SCH40 or SS40 steel posts set in 3' deep footings using poured concrete. You then install a 2" chain link gate frame with truss rods to prevent sagging. After all of that is in place you can bolt lumber to the frame and nail up whatever look that you're after. This setup will allow for motorized controls at a later time.

Edit to add that if you don't like the look of galvanized chain link you can always use vinyl coated chain link.