Depends on how you intend on building it and what angle the surface will be at. When you try to span larger areas the acrylic tend to bend especially if the acrylic it laying horizontally. My suggestion to counteract the bowing is to increase the thickness of the acrylic. If your setup is going to be vertical then the thickness of the acrylic can be less than if you were to build it horizontally. One of the main problems that I discovered is that acrylic gives when you press down on it. This bowing will increase the more horizontal it becomes due to gravity. The way I cancled out most of the give was to skrew my acrylic down to the aluminum rails thus, acting as anchors. From a camera viewpoint, you will have to fond a way to mesh camera inputs if you want your screen to be one contiguous piece. The field of view for webcams is limited so you will have to factor that in. You should also consider mobility if you are going to be transporting it anywhere. Don’t forget about projection throw and area! You might have to use multiple projectors or something.
