Perspective system advise needed.

My advice is to spell advice with a "c".

Well, for the prospective system… 
The Genelecs make a lot of sense.

As @djones51 mentioned:

You don’t need a DAC for Genelec the ones speakers

So the OP may be better off getting a sub than a DAC... (IMO).

You can have a nice system with any of the stuff listed in this thread. But you have severely limited your options for advancing your system

I think that the OP would end up with something that likely is fine sounding, without the hamster wheel of upgrading amps and preamps, and sources.

So it makes a lot of sense IMO to go with the fully engineered solution.

I would not worry about missing anything in terms of cobbling together preamps, amps, cables, and power supplies. The OP gets well down the road without (god know how much) waste in terms of extras to tune the system.

Thank you, russ69. A long time ago, I subscribed to this notion of future-fi or minimalistic audiophilia philosophy that your music could come from modern equipment, which does not necessarily have to be complicated to be great. For instance, many people report that room treatment was the most critical component in their setup. In contrast, others answer that great software like Dirac or Genelec's GLM could achieve the same (or almost the same) result with much less money spent.

Thank you, holmz.

Minimalism in audio (or Future-fi as some call it) makes much more sense than all those twenty-century creations, like preamps and multi-thousand dollars worth of room treatments.

I for one am firmly aboard the FutureFi bandwagon.  It’s hard to go wrong there, personal preferences aside.  

Still, my impression of a Terminator II and Terminator Plus is that these would give me a much more refined and life-like sound compared to the built-in DAC in my NODE streamer or most of the wireless speakers you have mentioned.

The speakers I mentioned don't have to be ran wireless you can connect them with ethernet cables. I agree with your FutureFi minimalism which is why I pointed out  the speakers you were looking at you don't need a DAC, more to the point using an external DAC would not change the sound as all of the inputs go through the built in DAC of these types of speakers. The analog input simply goes through an ADC first so while it is possible to use your own DAC it doesn't do anything except add another conversion and increase cost. 

I think you're on the right track with your philosophy but do a bit more research on the speakers you're considering.  The Genelec 8351b is an excellent speaker and in a small room I doubt a subwoofer would be needed for most music.