http://www.liutaiomottola.com/PrevPubs/Piezo/CoaxTransducer.htm
Inexpensive piezo parts sources and more piezo information:
http://windworld.com/products-page/electronic-hardware/piezo-cable/
More information on other types of pickups, preamps etc:
http://windworld.com/features/tools-resources/product-information/microphones-pickups/
Explore a little there, they have more information and links of interest to many of us as well.
Replies
Great first link too. I didn't know that the different kinds of piezo materials had differing levels of output - makes sense though.