Suggestions on hardware needed for.........?

There is no way I would go through all that just to avoid eye contact with this idiot. get a movie camera and just take movies of this guy doing the things you say he does and then call the Sheriff and play it for him. If that doesn't work, get life-like AK47's and mount them to turrets on your railing pointing in his direction. Barring all that, get 1/2" threaded pipe and flanges and bolt the flanges to the top railing. Screw the pipe into the flanges and at the top use "T"s. Then maybe shower curtain hooks. 1/2 pipe should be able to span about 6 feet before another upright support is needed.