Audio Science Review is a good source for information on audio gear.
Audio Hifi Equipment Reviews Stereo
www.audiosciencereview.com
They haven't reviewed the Sonos Era, but there is a thread in their forum about it.
Era 300 and 100 comprehensively leaked: https://www.theverge.com/2023/2/20/23606369/sonos-era-300-100-speakers-leak-features-price-photos
www.audiosciencereview.com
I agree that, if you can swing the cost, a good DAC and studio monitors (Genelec, Neumann, KEF, JBL and Focal are a few well regarded brands) will get you to a really nice place.