The PCCB is a rare option indeed, they had a 997 GT3 Gen II come in with the same problem you're experiencing. The discs and pads are not made for light use and thus will start squealing as the pad gets shiney. The way to cure is to drive very hard for a while, or to take the pads off and sand them down so the face is dull. The previous owner probably drove it around town and they never really saw any hard use. The pads are made by Pagid IIRC. Just make sure you never crack the discs, not cheap.
Lovely car by the way, did you test drive the Cayman?