I'm just trying to figure out what to get first to do it. The Node 2i seems like a good idea, and a good value for the money.

 I contacted Bluesound and I have to say they got back to e fairly quickly, not with info, but to say it might take them longer than usual because of covid. Thats pretty good service these days, when some don't bother responding at all.

 there advice when I did get it was to connect to my receiver with a single coax(not sure how one line can carry both left and right signals).

Then connect my powered speakers to the Node Analog audio out RCA left and right.

Its probably about a 50 foot run from my receiver to my speakers upstairs.What should I use for connects that are that long and will it be OK?

 Next question is how do I control what I'm playing in my bedroom? Do I use BlueOS app in my android tablet, and does that go thru the Node device to control what I listen to?.

Still trying to get my head around how this all works.

I had BluOS on a NAD integrated a few years ago and didn't like it at all. I stream Spotify Connect via Wifi now through a CDP/streamer and it sounds great and its easy to use. In my experience, Wifi streaming is better if you can do it. 

Download BluOs app on tablet, Get Node on your WiFi network then Connect Node to Speaker analog left and right replacing the Klipsch Gate. That would be the easiest way if you only want to use the Node with your powered speakers. If you have ethernet in your room use that instead of WiFi. The Node carries the audio signal all the app on the tablet does is control everything through the user interface. 

So If I say connect the Node to my Ethernet near my receiver then run a coax to the receiver, thats done.Just need a way to run it to my speakers in my bedroom.

According to this article

UPDATE: Amazon Music HD Is Still Lossy* by The computer Audiophile 2020

Bottom Line

The bottom line is twofold. First, it's great that Amazon Music HD can be streamed to a HiFi system losslessly in high resolution. Amazon's own applications are incapable of this, but fortunately the indispensable Bluesound Node 2i handles it with ease. If readers want Amazon Music HD, the Node 2i is a requirement in my book. Second, all of this testing indicates that streaming can be a mess for those of us who like high quality and care about the best sound possible. I think of all the conversations I've had with people who say one streaming service sounds better than another or their local copies of albums sound better than the identical versions when streamed. I completely understand. It's a mess out there.