Digital music questions

I'm somewhat new to hi res digital audio and I'm looking for some tips. I have been building my system and have purchased McIntosh c2700, which has a DAC built in, a 462 amp, and B&W 802d4s. Using Apple Music, I have been streaming music through a Macbook Pro via a USB cable to the DAC of the c2700 preamp.

The McIntosh preamp states the streaming quality is 44.1 kHz, which seem to be the low end of high-res streaming. I currently have so many subscriptions, including Sirius XM for the cars and Apple Music for my family, and more recently Nugs for concerts, (not to mention video subscriptions...seems it never ends), so I was hoping not to add another paid subscription.

That being said, am I leaving a lot on the table? Would a dedicated streamer sound a lot better than the Macbook Pro? Are there streamers without DACs, so I can use the McIntosh DAC without purchasing redundant equipment? I understand I cannot use Apple Music to get high res audio to the preamp, as they only provide it through Apple equipment at this time. Can I get a streamer that uses the DAC of the c2700 preamp? Finally, do I then need to add another subscription, such as Tidal or Qobuz, to get high res audio? 

Thanks....it's a lot of questions, but I'm sure someone here can help!