craftgrrl | Mask help.

Hullo, this is my first post here, but I've been lurking for awhile. I'm working on a mask for my prom [masquerade theme is fabulous] and I was hoping you all could give me some advice:

What would you use for the base structure material? I am planning on getting a cheap plastic mask to build off of but the mask, a jester mask, is going to have the pointy bits coming off which need to be able to bend [but not flop over] with the decorations to give it a "drooping" effect. Would layered poster board work?

Thanks!