So, just use plastic stuff, toys, car parts, kitchen utensils, some electronics and paint to make it look nice! The electronics are even optional, it looks just allright without it.
The paint I used first is reseda green, this is a nice copper green color. Just apply everywhere you want copper. Add a layer of copper spraypaint, but don't overdo it! Add some touches of matte black and voila!
Have fun steaming you punk!
You can find the Arduino file here: https://sites.google.com/site/benadski/steampunkin