My set up includes the K702s, FubarII USB DAC and Spotify and Spotify is by no means the weak link. Spotify streams at the highest bit rate out at the moment with its premium service at 320kbps. Sky Songs streams at about 16kbps (yes, sixteen), yet some prefer it to Spotify. More important than the kbps is the format used and Spotify's Ogg Vorbis is great.
I am confident that your suggested setup will sound fabulous. It will drip with detail, rock when required and give you a super hifi experience.