If you want to control each room separately using Sonos, you’d need a Sonos Amp for each room, assuming these are passive speakers.
@richardibarnes,
Is the mentioned CD Player linked to an Amp and does the setup currently allow the audio to play to each/all of the zones separately/together? If that is the case, you could likely add a Sonos Port to the same Amp as another line-in audio source …and then use the music services available via Sonos and play all to your speakers, but it depends on how the setup is currently configured / type of hardware you may have already.
If that’s the case, note that the Sonos Port, just like the CD player, is a single audio source, and does not supply 8 different audio streams simultaneously.
Is the current system functional? If so, replacing the CD player with a PORT would get you going. How does the current system control Volume in the rooms? Are there any in-wall or central Volume controls? If you want eight truly independent SONOS Rooms, as stated above, you would need eight AMP’s.
If there are in-wall Volume controls, it may not be necessary to have eight truly independent SONOS Rooms. For example, a bedroom-bathroom-closet suite may not need independent feeds in each area and could be attached to a single AMP, however, you would want the ability to balance the Volume in each area, ideally with local in-wall Volume controls.