Stellar Gain Cell DAC , RME ADI-2 or other with Node 2i?

I’m considering using an external dac with my system currently composed of :
Odyssey Kismet in Khartago amp
Ascend Sierra 2 EX 
Bluesound Node 2i
Rel S5 SHO

I’m streaming through IPhone via Qobuz and Deezer Top tier and don’t really think that I will ever add a CD player or turntable but you never know. 

It it seems that my prime candidates are a used PS Audio Stellar Gain Cell Dac or RME ADI-2 at this time. 

Both of these feature preamps and I think that down the line I will probably add a tube preamp (possibly a Odyssey Candela?) as funds allow so , they may be overkill? It seems to me that at the (relatively!) low cost of those Dacs that a preamp would just be a plus anyway? 

Should I prioritize a tube preamp before getting a dac or visa versa? Should I even get a tube preamp? What about upgrading to a Blueline Speakon for the sub and/ better power cords first?

I listen to all kinds of music btw.. 


Also, what would be the best way to connect everything anyway? I have Groneberg interconnects from Klaus but they didn’t fit the Node 2i. Would they work with those Dacs? 


Chord Qutest DAC (no preamp) goes well with Node2i
My recommendation would be a Shunyata power conditioner first, then a respected tube preamp.  The Node 2i responds positively connected to a Shunyata Hydra Triton in my big system.
Thanks so much for the suggestions pc_audio and rhljazz. 

I’ve heard that Chord has a great rep and will definitely be a top option for me on down the line. 

I have realized since my original post that i’m Really over-extended and so will need to wait for several months before I make any more purchases of even just several hundred dollars. This will give me time to keep researching and plan my next addition (s) though so please keep the suggestions coming.

Rhljazz- I also unfortunately don’t think that I would ever be able to afford such an expensive Shunyata (or other) power conditioner. I will take your overall plan into consideration though. So you really feel that it should go power conditioner then tube preamp then dac? 

Thanks again! 
I have a Node 2, and recently purchased a RME ADI-2 DAC. My set up:  Tidal > Bluesound Node2 > Wireworld Super Nova 6 Toslink 1M > RME ADI-2 DAC > Zu Wylde 0.5M IC > Woo Audio WA-6 (first generation with Sylvania VT231 & RCA 5U4G) > Massdrop HD6XX.
Airy, natural sound, with nice body!