The acoustics primer here on the home page should be your first stop. Read some of the stuff there first.
You have a very interesting room, that provides some unique challenges, but nothing too horrible.
First off, I would consider moving everything 90 degrees so that the video and main speakers are on the long wall.
Nice goldens! How the heck did you get the three of them to line up for that portrait? It seems like it would be hard enough for one!