Help a digital luddite

I have enjoyed putting my current system together over the last few years with an emphasis on vinyl and cd/sacd playback.  My current system consists of the following:

Marantz PM 11S3 integrated amp
Marantz SA-11S3 SACD player
Manley Chinook phono preamp
Music Hall MMF 9.1 turntable
Clearaudio Maestro cartridge
Focal Electra 1028BE speakers
Focal Chorus SW800 subwoofer

This system has proven to be an excellent balance of clarity and musicality in my 14'x18' listening room. My tastes run the gamut with a fairly heavy emphasis on blues and jazz and a healthy dose of both classic rock and "alt country" artists.

In an attempt to interest my millennial kids in joining me in listening to music, their response has been to ask why I do not have a way to listen to digital formats other than CD's.  While I defend the quality of my chosen formats, I frankly am too simple minded to understand the best way to incorporate either streaming audio or downloads on their laptops.

I have no interest in abandoning my current components but would like to supplement them with equipment of comparable price / quality.  My PM-11S3 has a well regarded built in phonostage, but upgrading to the Chinook made a meaningful difference.

According to Marantz, my Sa-11S3 SACD player has the following features:

"Digital versatility is the hallmark of the SA-11S3, as the player does double duty as a reference quality DAC and is equipped with numerous digital interfaces to accept a wide variety of formats. The front panel features a USB-A port for connection to a portable device such as an iPod, iPhone, iPad and the like, as well as compatibility with other devices. There's also a USB-B port on the rear panel, which provides compatibility with a wide range of digital formats, including up to 192 kHz/24 bit digital audio, and is compatible with asynchronous data streams from a computer (drivers are available for download on our website). In addition, there are coaxial and optical digital input ports for connection to other digital audio sources."
 
So - how do I best incorporate digital input from either my kids' laptops or a streaming service? Are any of the features of my SACD player sufficient to meet these goals or do I need a freestanding DAC or other piece of equipment.  If I want to just use my current equipment do I need any special cables?  Will a freestanding DAC dramatically improve sound quality over the built in DAC? If, so, any specific DAC recommendations? I am generally aware of the difference between compressed vs uncompressed files, but my eyes glaze over when talk turns to the various formats (mp3;wam;wav;mic;key; mou;se).  My goal would be to either achieve SQ comparable to my SACD's or better or just forego the effort.

I greatly appreciate any guidance you can provide.