how do you stream ethernet quality in a non ethernet (wi fi only) room

You can use an extender like @ghdprentice does in his system 

your other option is a mesh network like EERO or Google Mesh…there are many. 
You kill few birds with one stone - improve internet speed of your wifi throughout the house and provide a solid high speed network connectivity to your streamer. 
 

If you want to do wifi only, one of the best in this space is the Auralic line of streamers. They cache to memory and sound good when setup as wifi. Assuming there’s enough bandwidth in that room. 
 

There are cheaper options as well…Cambridge audio is one. 

Laptops are usually not the best streamers. Will it work? Yes. But it will not sound as good as a good quality streamer. You can have your downloaded tracks either on an external drive that you can connect to a streamer or on a network storage that your streamer can access. 

If you’re looking at streamers that cache and are willing to use an extender or mesh network, Aurender is a great choice but needs to be hard wired. 

@cleeds wifi dongles typically connect to a USB port and require a driver on a device they’re connected to in order to work.

The version of the “wifi dongle” you can connect to Aurender is either the wifi extender or the mesh node/access point. It needs make an Ethernet connection  

If you stream from a laptop, all modern laptops have built in wifi.

@cleeds 👍