If you're only going to run two initially I set them up in a gyre. Since you want the right side clear for viewing, mount one pump on the right side of the back pane as close to the corner as you can and aim it towards the center of the front pane. Put the second pump on the left pane of glass as close to the front of the tank as you can and aim it towards the center of the back pane. You want to push the water across the tank, along the glass to the next pump, and repeat to create a wide circular flow. Doing this will allow the pumps to aid each other in creating flow.
