Check to see if the wiring is still there. Wiring would have fallen behind the battery on left side of boot. Should be 2xRCA conn and a Circular DIN style Conn.
Besides a factory reco Changer any older style Sony 6Disc CD Changer will work.
Hi, another alternative is the Becker Silverstone 2660, which I believe is the same as the factory fitted unit but at around the £270 mark it's probably a little more expensive than getting an old sony changer.