Any Single Speaker suggestions for use with chromecast r

I've been looking into some speakers to use with Chromecast audio but can't seem to find a good pair to use. I'm considering buying the Sony speakers (zr5 for example) however I worry if they will work well if I decide to get a different brand speaker with cca built in and eventually a receiver for outside to stream music. Instead I am contemplating buying 2 Chromecast audios and connect them to independent speakers.

So instead I'm looking into a standalone speaker with an aux input for cca. I don't know if a bookshelf or a monitor speaker would work best or something else entirely. I only want one speaker as to minimize the footprint in the kitchen and living room. Any suggestions for a speaker I can put in 2 rooms with 2 cca's ?