Hi,
I shot a short two weeks ago using a HVX-200 and, like your director, we wanted something a bit more "interesting" than 16:9, so we went for 2.4:1
I masked off the pull out screen on the camera to 2.4:1 and the also the directors monitor to 2.4:1. Due to the assignment regulations (it's a project for uni), we have to project it and hand it in in 16:9, so we're using a 2.4:1 window as a mask. The handy thing is that if it's decided we want to slightly change the framing of the shot, they can be moved up or down under the mask. I'd recommend this method, it looks pretty sweet.