The drop ceiling stuff is probably easier to cut and harder to control, but it would work just as well.
The 'acrylic' stuff is REALLY brittle, and cracks spread like a devil. I think I saw there's some 'poly' stuff now on the market, but if it's any thing like polycarb, which I think it is, strong and stable as heck, but right mess to cut.
Course, I've five thumbs on each hand, so YMMV may be assumed. Too bad, as it would have made a great looking sea surface overhead for my never-realized Captain Nemo meets the Deep Ones game.
Doug