Do you have the original woofers? If so, there may be useful part information printed o n them. I am not 100% sure that the woofers were Philips drivers (e.g., they may be from CTS or another, similar OEM, rather than Philips).
Why do you need to replace them, if I might ask? If only the foam suspension (surround) is deteriorated on a driver, the suspension itself can be readily replaced (in case you didn't know that already).