A hobby/craft store should have lots of wood pieces for making all sorts of models for airplanes, toys, no telling what else. I haven't visited a craft store enough to know for sure, but surely they have a cache of wooden model supplies.... likely light weight balsa wood or similar.

Small model motors, if need be, and other hardware for models or miniatures..

Styrofoam, also, for a pre-mockup of some aspects?

Sonny