Need helpful recommendations for next two purchases


So I'm 73 just getting back into two-channel. So far I've purchased from Adrian ( great guy highly recommended) on Audiogon a pair of Canton 9k reference speakers with stands, and a Jamo c80 sub, and fancy speaker cables Wooo the hook has been set lol.  Oh and thanks again for the Canton feedback.  The Cantons are powered by my 30 yr old Adcom gfa555 250 watts per, Emotiva  XDA-1 preamp/DAC (24 bit/192 kHz), And a new Marantz CD 6006. The Marantz has a USB port which is set up for an iPhone, it also has a headphone amp and a DAC that can drive the amp directly. 
I know jack about streaming but believe it should be my next component. My question given the level of my system and a budget of about $600 what should I be considering for a streamer or whatever it is called to listen to music through Roon or other similar sources from the WWW?
 It seems the one's I've looked at are all Preamp/DAC/Streamers such as CambridgeCXN V2 ( way over budget) Marantz NA6006 and Bluestone Node2i both in budget.The problem is all three seem to be duplicating what my Emotiva already brings in the way of a preamp/DAC so why should I spend $$ for stuff I have already except if one is better then the Emotiva at preamping and DACing   OR are there just streamers I could buy please show me the way. Oh while I like detail the above system could use just a little warmth it is not bright or forward almost just right. Almost ... I see it coming lol it is always going to be almost.

An extra credit Help question I will post a bit down the road but you  could get me researching now what to replace my Adcom GFA 555 ( quiet as a mouse nothing leaking or bulging inside but its 30 years old) and at 73 I know what age can do that you can't see.
My budget is $2000+- I don't mind used but can't afford to by a Krell, McCormick, Bryston etc. and then get hammered with another couple of grand in repairs. Did I mention I'm retired on a fixed income, Scottish with a dear wife that I want her to remain so.  Oh while I like tubes at some level  I'm not a tube guy can't afford the upkeep or temptation to roll tubes. My shortlist to be researched beyond just their names include: a few pieces of Schiits,  XTZ A 300 or 2 biamped, Emotiva base X a 300 or 2 bi amped or Emotiva stealth PA1 biamped. I worry that Emotiva amps will add to much brightness forward sound. Also looking into a built kit from Akitika, Rotel RB1552 mk2, Optoma NuForce STA200,Nu Prime st10. At this point, these are just names do you like any? Do you have any other amps  I should consider given my set up noted above?
The room 12x16 vaulted ceiling 8 ft to about 18 ft system out 2 ft from the  8 ft wall.  WW carpet, 2 overstuffed chairs on either side of speakers.  lots of hanging plants ( in corners) three big glass windows behind my system, one glass sliding door to deck comprises one short wall,the other short wall has 8 ft opening,  behind my couch that faces the system is a wall with a big glass picture  2x3 ft. that long wall facing the system has plants in each corner and hanging baskets in each corner. Not a lot of echo despite all the glass life's a compromise. Thank you for reading all this stuff and for your kind recommendations. Be safe stay healthy listen to music.  
scott22
I recently jumped into streaming with a Node 2i and a Tidal prescription. Got my wife on board when we figured out the Node can 'tune' (stream) local radio stations as well. The learning curve was pretty easy - I'm controlling with a computer, or my android phone, she uses her I-pad.
We're also very close to retirement...Keep the fun going!
+1 @kairosman
For streaming you can try a Raspberry Pi based solution, there are a couple. You can also assemble the RPi yourself if you’re good with computers, then the cost may stay below $100.

https://volumio.org/product/volumio-primo/

https://orchardaudio.com/shop/ols/products/pcnp-strmr

https://darko.audio/2020/01/raspberry-pi-audio-streaming-101/
I would look at a portable WiFi enabled digital music player from FiiO and others.  These have capable DACs, some can be a Roon endpoint, and you can run them on their rechargable batteries, removing them from the grid.  Just add a good 1/8th inch to RCA breakout cable, and you are good to go.  Plus, you have a player that you can use on the go as well.
You have a lot of good recommendations and it can be confusing for someone just getting into streaming. For simplicity I would recommend the Bluesound Node2i. It has a built-in DAC that is ok but most stand alone DACs will outperform it. The Node2I can be used with its internal DAC or you can use your own stand alone DAC.

I would go with an integrated amp to replace your Adcom and Emotiva. There are many good integrated amps out there from Yamaha, Marantz, Denon and others. It depends on how much you want to spend. Many have built-in DACs that may be better than the one in the Node2i. You might want to check out the Yamaha A-S801 or A-S701. They both have a nice built-in DAC and you could compare it with the one in the Node2i to see which sounds better in your system.

I would recommend purchasing from a retailer with a liberal return policy in case you are not happy with the component.

 
Again thanks for all the advice  I have not listened to many systems so my frame of reference is severely limited.From what I've heard from youtube videos of audio shows Woo my gear is like 10% of what I hear but also 1/100 the cost. My budget is $5,000. I've spent $2500 on speakers and CD player the node2i would extend my listening range so thats $500.Therefore I've got $2,000  to use for an amp and later a better preamp/dac.I'm using cox cables for interconnects and speaker cable is from Maker Audio I'm fine with that. 
  Currently, my system sounds very good to my hearing (wish I could upgrade my old ears), from where it was prior to the Canton, Jamo sub purchase. It does not sound etched or bright to me. Piano, sax, sound real to me Chet Bakers' early voice still sounds silky but certainly not tubeish nor would I want it to be. Tubes do not sound natural nice for sure natural not to me. I would say currently my room is the biggest obstacle and the only way to improve that is by a divorce no way that's going to happen.