At the end of my research I decided to go for Interphone Tour.
BT 4.1. Can pair up to 4 devices, also can pair other brands which is nice extra. Fully waterproof.
Tested in pair as a intercom, and just only for phone call/ music listening. can't say so far any bad word about it.
Connect, power on and works without any issues. Android app for quick settings change if needed.
Generally modern intercom set.
Will tell probably more after few months use.