Not sure about OneDayGlass.com, but I went to a local glass shop. Should be easy to find in your area. They made me a replacement for the plexiglass that was in my original cabinet. I just took it in to them, they measured it and I had a new piece the next day. Did not have to worry about paying for shipping or damage in shipping.
I got some 1/8" thick tinted glass and it worked perfect. I thought it made the cabinet look better as well as the image from the monitor. Make sure you go with GRAY tint. The tint hid a lot but I still made a bezel as I wanted everything hidden. The darker will hide more, but you may have a problem if you plan to use a light gun.