Streamer upgrade


I need recommendations for a new streamer that will replace my Sonos Connect.  The rest of the system, developed largely from AG recommendations, consists of Fritz speakers, driven by a Primaluna EVO100 integrated. Sources are a Clearaudio Concept table and Cambridge Audio CD transport through a Schitt Bifrost (also handling DAC duties for the Sonos).  I'm using Amazon HD as a streaming source right now.  This system doesn't need to integrate with  my other Sonos speakers.  It's my intention that this be an end-game system, so I'm looking for a streamer that's appropriate to its level rather than something that's going to lead me down the path of perpetually upgrading other components.  Price is a secondary concern, used gear is fine.

Thanks for any advice - truly appreciated, and I'm grateful for all of the forum help I've received in the past.
philiptamarkin
Steamer only, or streamer with integral DAC? I ask this as the Bifrost will be the limiting component if you go streamer only.
The choices are myriad.  I know that SOtM, microRendu (SGC) and others DO NOT play Amazon HD look before you leap. Proprietary and subscription Volumio DOES. At least you don't have to worry about DSD with the Bitfrost - nada.
After owning a number of streamers I converged on Aurender. They have complete lines with and without CD. I highly recommend I have there N100 and flagship W20se. They are of outstanding quality and build. Built to last a lifetime. They understand how to do power supply for no noise and an astonishing level of detail, natural sound and dead quiet background. 
Thanks for the recommendations.  Not married to the Bifrost if there are other options available.  Not married to Amazon either after a really frustrating day of getting it to play with the Sonos...