I'm sorry, but I wouldn't call that a rack mount solution. It's more like multiple Sonos units on a rack.

There are some freestyle solutions in there for specific locations, but if you keep scrolling you'll find some actual 19 inch rack solutions too.



If you do really like Chromecast Audio, take a look at the NAD
CI 980 and
CI 940. With one of each and six Chromecasts you would be done.
Then you could just as well buy a
Dayton Audio MA1260 and be done with it in one unit and half the price.
Sure you can. There is audio gear for every price point.