I own a performance brake company and I've got a kit put together for PT Cruisers. These are stock size parts and they won't break the bank.
Front and Rear Slotted or Crossdrilled Rotors
Front and Rear Posiquiet Performance Pads
All PT Cruiser NON-turbo w/ Rear Disc: $279
Front Kit only: : $179
You can view pictures of my rotors here
http://stopitbrakes.com/upgrade1.htm
If interested or for more info, please email me:
pat@stopitbrakes.com