Do I need a new DAC/streamer. Considering?

I would rather not duplicate DAC’s. The DAC in the C53 is upgradable when necessary is the reason why I bought it. 

i know the Node is not in the same league as the rest of my equipment. Even though it’s pretty good  

Again, it’s hard, for some reason, for me to think that Just a streamer, without the DAC,  can make a significant difference in sound.   As you are aware, I have a few dollars tied up in my system.
 However, the diminishing return theory plays a part in my decision

Look for a used MHDT DAC, may take awhile but damn they sound musical.
AtlantisIstanbulStockholmOrchard

You could absolutely add just a server/renderer. I was shocked when I added a Nucleus+ to mine. Made more of a difference than moving from a Marantz Reference DAC to PS Audio DSD.  Server is way more important than you would think.  

When I added it, I was running a PS Audio BHK Pre, PS Audio DSD and VTL MB 185s....not a small investment either.
I have since done a lot of investigating and the weak link in the chain is the Server. Antipodes explains this pretty well. The internet is volatile and needs something powerful and stable as data comes in. The renderer actually requires less power.
This has a huge impact on sound quality. I was very confused when I added my server and it improved sound noticeably.
The best possible solution it to separate the sever, renderer/player and DAC. This is more because the server is better if it doesn’t have to deal with the secondary load of renderer as well.

Given the rest of your equipment, I would definitely entertain a Lumin X-1.  I have had the D-2, A-1, U-1 mini and the X-1.  you can sell off the your other digital equipment and just use the X-1.  I just sold my X-1 because I wanted a Tube DAC to go along with the rest of my tube amps.  I bought the Lampi Pacific at three times the cost.  I will say the X-1 is a very close second.  

I had a separate DAC, Music Server and Transporter.  I was able to sell them all and just go with the Lumin  X-1.  The sound is really really good.  The App is so easy to use and you don't need Roon.  I did have a 4tb Synology NAS where all of my music is filed.  I think the Lumin X-1 is the best DAC / Streamer under $19k.  They show up on the used market occasionally.  

I recommend Aurender N100C, that would pair well with your C53’s internal DAC. Aurender’s Conductor app is also excellent. It would be a worthy upgrade over Node 2i.