What is the best way to stream music from itunes on a Mac to a stereo system now that Airport Express is discontinued?

Hi all,

I'm going to sound like dinosaur, but I'm looking for the best way to wirelessly stream music from my iMac or Macbook Pro to two different sound systems. I have one Airport Express Gen 2. I'm willing to find another discontinued Airport Express unit for the other stereo system, or third party wi-fi extender with an audio jack, but it seems these units only support up to wi-fi standard 802.11n and not sure if all extenders support airplay, even if they have audio mini-jacks.

I happen to like the way music sounds on my Denon and NAD sounds systems with Polk Audio speakers. It seems the industry has moved to bluetooth or standalone speakers.

Is there a better way, or do I have to try aging wi-fi extenders that I can find from Netgear or Linksys?

I suppose I can run the music through my Apple TVs to the wi-fi systems, but I hate the idea of turning on a TV just to listen to music.

Equipment on my network:

iMac 27 Inch (Mojave), Macbook Pro (High Sierra), Airport Extreme Time capsule (4TB), Airport Express Gen 2, Netgear Extender (no audio jack), iPhone 6s and iPad mini Gen 2, ATV Gen 3, ATV Gen 4.

Thanks in advance.