Network Audio Player - need some basic advice


I am a bit of a Marantz fanboy and currently listen to mostly vinyl and cd's.  I have over 500 of each and never seem to be short of listening options. I use a Marantz PM-11S3 integrated amp and an SA-8004 SACD player.

This weekend my boys pressed me on why I cannot access music online.  Being an old fart, I had no response other than to offer to play them some of my vinyl.

Shamed by my spawn, I tried to read up on what was offered by Marantz in this category.  With at least  four products (NA-6005; NA-8005; NA-11S1; HD DAC-1) spanning in price from $649 to $3,499, I quickly realized I had no idea what the basic selection criteria should be - there are so many formats I am unfamiliar with as well as a variety of input connections.  In addition, I am quite concerned about the obsolescence factor given how rapidly these formats seem to change.  I also do not understand why some have wireless connectivity and some do not and whether this is a big deal or not as my system is on a different floor than my incoming service.

 My SA-8004 has a USB port on the front and coax and optical inputs /outputs on the rear, plus an input labeled "USB DAC" which is an unusual shaped input unlike the usb on the front panel. The PM-11S3 only has RCA inputs.

Can someone give me ( or point me to) a basic primer on this topic? What are the essential features to look for?  I am a complete luddite, so it needs to be REALLY basic, i.e. the more acronyms used, the more my ears begin to bleed.

I love my other Marantz gear, and start with a bias towards the brand , but are they offering a good product line for this, or are they behind the curve.  If not Marantz, then what does more for the same money?  If I cannot plug directly into my internet connection, is there a device I can buy to make a wireless connection?

Given my preference for vinyl and cd's, I do not want to spend a ton of money for another piece of gear, especially if it will be obsolete in a year or two.

Thanks in advance for any guidance you can provide.

sjtm
I recently bought a Bluesound Vault 2.  Just about have half my CDs loaded on it, but it also does internet radio and streaming from most of the typical streaming services.  At $1200 for a 2TB system that RIPs Cds and has a decent tablet control interface, I'm happy with it.
Hi SJTM,
I am like you, complete newbie to streaming and the lots. I currently use a laptop for access to all the music I need and send it to the sacd player, (sa8004 has a built in dac), via a good usb cable. I can play physical disc or listen to any radio stations or play ripped or downloaded music through the sacd player. Oh, I have the similar unit as yours, but a later model sa8005.
Digital music is still exploding and quite expansive now. Waiting for the prices to level off and the gears to stabilize. Too much choices and wide price differences now. 
Hope this helps.

Since you are just getting started it might make sense to dip a toe with a Chromecast Audio.  They are available at Best Buy or you can order from Google. Super easy to control via Spotify or Tidal app on a phone/tablet and sound quality via optical (into your SACD) is much (much!) higher than you might expect for $35.  It's probably the best bargain in audio today.  I listen to 320 kbps streams from Spotify much more than any other source format these days, just because of the ease of use and outstanding recommendation engine.