Acrylics are quite strong but not as strong as metal cases. Check
here for shops that sell them.
You can even laser-engrave text and logos on the acrylic case. I'm making an acrylic window for my rig. The company I work for makes plaques and awards. I'll have the production dept. engrave something
However, acrylic cases gets scratched. It takes quite a force to scratch them. But I don't know if it can be fixed if they do get scratched. On the other hand, we can easily re-paint metal cases.