If they want to "jam out", or just prefer the clean look of the ceiling 'speakers, the new Sonos AMP would be a good option.

https://www.sonos.com/en-us/shop/amp.html

If the AMP doesn't support Alexa out of the box (I'm not sure, most of the newer Sonos products do), then get an Echo Dot (only $29.99 right now or 2 for $50! https://www.amazon.com/dp/B0792K2BK6) and to setup:

https://support.sonos.com/s/article/3439?language=en

​