This circuit can easily be built on a solder less breadboard. The components are widely available at low cost from a number of sources, such as DigiKey, Mouser, Jameco, etc. that you may already be familiar with if you work with electronics.
You will need a programmer for PIC microprocessors. I have seen instructions on this site for building your own programming device, but I cannot speak for any of them. The programmer I use is from a company called Micro Engineer Labs, Inc. at http://www.melabs.com
It is also handy to have an audio generator of some sort, for testing and experimentation. This can be as simple as a connection to the line out of a PC, CD player, MP3 player, etc.
For example, to verify that the circuit works to detect a certain frequency, just play a file containing that frequency, with the audio output of the playback device connected to the input of the circuit.
A useful program for generating sound files can be downloaded for free at http://www.goldwave.com
. This program allows you to create *.wav files containing specific tones, sweeps, etc. very easily.