Hardware Prototyping on the cheap

Who makes or prototypes cases/shells for appliances like Routers or
PDA/Handheld? I have the internal components using ARM technology (like
internals of a PDA) and want to put a clean usable box around it for
initial customer use. 2 Solutions could exist: 1) generic off-the-shelf
boxes/handheld-shells that I could put my components in for a prototype
2) someone who builds professional boxes/Handheld-shells for prototype
(Note: money is VERY limited for these shells so prototype may not be
an option now).

Thanks