Well, I did my research today and was actually stunned to find out how many different kinds of ceiling tiles there are!
Doyboy - can you help me narrow down the scope a little bit? Above you indicate that the sheets are 4x8, so that narrows it down a little bit already, but still leaves quite a few choices!
Because they're 4x8 is it safe for me to presume that these tiles are nested in a racking system which is suspended from the ceiling above, and attached at the walls? If so, are they plain or patterened? Are they white or another color? Are they a heavier rigid panel, or a more lightweight panel that is slightly flexible?
If the panels are more rigid, is there a pattern inset into the face, or are they smooth surfaced?
Any descriptive information you can provide will help me narrow down to just a few choices.