Hello,
I’m building a house and am considering building in SmartThings integration as a Smart Home.
What speakers and audio amplifiers for whole home audio would be available?
We have 1 Android and 3 iOS devices in the house. TVs are 2 Samsung and 1 TCL with Roku. 1 Sonos speaker in the house. I’m considering adding some Amazon Echo devices in the house as well.
Any help is appreciated!
Both Amazon echo and Google Home work well with SmartThings as far as accepting verbal home automation commands, and there is a partial integration with both Sonos and Samsung speakers, but there’s nothing built into the official features for SmartThings which allows you to control playlists or anything down to that level of granularity regardless of the particular device you choose. 
You can see what other people have done for custom AV projects by checking the quick browse lists in the community – created wiki, looking in the project report section, and looking on the AV list. 
@pstuart might have more to add.