First off the schematic is in the first post, the three main parts you need are the interpreter chip the EEPROM and the resonator. you will also need some simple components such as resistors, transistors, and a regulator (refer to the schematic). the interpreter chip, the EEPROM, the resonator, and the regulator you can get for http://www.parallax.com/
look under OEM components (they also sell a kit but it's $30.00) the rest you can get from any electronics company I got mine at www.jamco.com
(they also mite sell the regulator and EEPROM).