The Pioneer or Onkyo surround sound receivers are suitable for using Sonos speakers, as they have an integrated Sonos Bridge function. I would recommend this one, it is much better equipped than something from Teufel and I would then digitise the CDs if necessary.
Onkyo TX-NR6100 (7.2 channel, FM, DAB+)You can also use smaller Onkyo models, but the NR6100 is much better equipped than the smaller ones and also has the latest audio technology on board.