@audiobuddy there are few different options here. You have streamers and music servers with a built in DAC such as Auralic Altair, Lumin D2, Aurender A200. This category units usually would have their own UI. Auralic’s Lightning DS, Lumin’s UI app and Aurender’s Conductor app (not Roon ready).
Then you have DACs with an onboard network renderer such as PS Audio DSD, Bricasti, and the above mentioned Gustard. These are going to be Roon ready or compatible with apps such as Mconnect. Digital to analog conversion will be the primary focus of these units, with the network renderer being good enough but not on par with a dedicated streamer in $3,000-$4,000+ range.
If you want a one unit integrated solution and are not looking to have flexibility to upgrade the streamer alone, then the streamer/music server with a built in DAC is what you need. If you don’t need Roon, go with Aurender (although there are constant rumors about future Roon integration/certification). Other than that, Lumin or Auralic are good units.