albeiro, depending on which way you go, I don't think it would be a big deal at all to run something else alongside SONOS.
For example I run two wireless streaming solutions concurrently to stream to a variety of devices including my good in home hifi systems and remotely to various wireless devices (including computer in my office at work) over internet:
1) older Logitech Squeeze System (wifi)
2) newer Plex (wifi and Bluetooth)
Each works different and has different features to learn but no problem running both concurrently.
If you wnat a single solution, don't see why you could not continue to use Sonos devices. You might want to run an external DAC if the sound quality is not up to snuff out of the box.