To Stream ...

Here's what I've got:
PS Audio PerfectWave transport
Chord 2Qute DAC
Modwright SWL 9.0SE Preamp
Butler 2250 Amp
Modified Maggies (by Peter Gunn)

What I'd like to do is stream from a service such as Spotify.
--I mention Spotify as I currently use them to stream music to my iphone when I'm out and about and I've just heard they will soon be streaming in lossless.
I know little about streaming and after reading through a few threads, don't feel like I know much more about it.  I hope this isn't a sign of my older brain.
I currently receive quite fast internet service via a cable modem and then a router that provides ethernet cables that run to various rooms in my house.

The question: What do I need to buy that will plug into one of those ethernet cables and take the streaming Spotify data and feed it to my preamp?
Is there such a thing?

And let me state now, I understand the audio quality will be less than what I'm currently used to but that will be OK for the amount of time/type of listening that will occur while streaming.
And the emphasis here is simplicity: one device that does this, not a bunch of things with a bunch of connectors ....or building something myself (not doable).
Is there anything out there that fits this description or is my question semi-nonsensical and reflect my inadequate understanding of the concept of streaming?