Frank is correct. A glass-beaded screen is not appropriate for a home theater. You are definitely on the right track by thinking about going to a fixed screen application. The fixed screen will allow you to use a stretched vinyl fabric rather than one that has a fiber-glass base to it. This makes for a much flatter screen with no edge curls etc.
However, to answer your question about the material. The glass-beaded fabric you have is a 2.8 gain screen. The Draper M2500 is a 2.5 gain screen. The biggest difference in the two is the fact that the Glass Beaded is retro-reflective and the M2500 is reflective. What that means is when light hits the glass beaded screen it bounces back in the same path it arrived. Conversely, when light hits the M2500 it bounces back at an angle equal and opposite that of which it arrived. If your projector is ceiling mounted, you need a reflective surface not a retro-reflective one.
Now on to the question of gain. You mentioned the Draper M2500 fabric and as I stated earlier it has a gain of 2.5. That may be a little hot for your projector. You have a Barco 808 projector that is a CRT projector and is inherently non-uniform. Therefore, the higher the gain of the screen the more accentuated the hotspot is going to be. Therefore, if you have good control of the ambient light in your room a gain of 1.3 or 2.0 is preferred. However, I would not go over 2.0. If you do you will start to show the hotspot and you will narrow the viewing angle of the screen.
All three of the big screen manufacturers have screen surfaces with 1.3 gain. Both Da-Lite and Stewart's screens are ISF certified. In addition, I know that Da-Lite is one of the only companies that has a 2.0 gain surface. They call it Pearlescent. It is a reflective surface, as you will need.
Hope this helps,