First remember that the hardware platform (sound bar, smart speakers) should not dictate what music service you use. With a few exceptions (eg Apple music is not available on all hardware platforms) most services are available on most hardware.
Second it is not clear what you are trying to achieve. It appears you already have a whole house wireless audio system and a sound bar that integrates with it, right?
What is the problem with that system?
If you can define that, I suspect folks can advise you. For convenience, the SONOS system is very good. For your budget, you could afford to add their overprices bass module (they call it a sub but it is not a sub, it's just a woofer) to an ARC and have a few Sonos 1s around the house, and it would be super slick.
But I'm not sure if it is a two thousand dollar better than what you already have.