You can connect the Peachtree directly to your PC via USB if proximity allows. If the Peachtree is setup in another area then the Sonos is a great product and I agree with Arni's suggestion of the coax cable interconnect.
This will be a nice setup but I feel MP3 will not do it justice. Try some lossless audio (16-bit/44.1 kHz) and you will hear a big improvement. Move up to 24-bit/96 kHz for an even bigger improvement (from your PC as Sonos does not support 24/96). Once you have listened to some high resolution audio you will really appreciate the Peachtree.
Whatever cable you choose will have less impact than your source material's resolution and bit rate.
This will be a nice setup but I feel MP3 will not do it justice. Try some lossless audio (16-bit/44.1 kHz) and you will hear a big improvement. Move up to 24-bit/96 kHz for an even bigger improvement (from your PC as Sonos does not support 24/96). Once you have listened to some high resolution audio you will really appreciate the Peachtree.
Whatever cable you choose will have less impact than your source material's resolution and bit rate.