Recommended Server?

As a streamer only for a music server.

Aurrender. I own two after experimenting with others for years (you can see them in my virtual systems). The higher level one you buy the better the sound quality. Aurrender only makes streamers and they are among the best, if not the best at various levels. 
 

I only listen to Qobuz… although I store my old ripped files on it for the very infrequent internet interruption. 

As a streamer only I would recommend the Martin Logan Unison. It has ARC room correction which works great and is on sale at 50% off:

https://www.martinlogan.com/en/product/unison

Review:

https://www.techhive.com/article/582813/martinlogan-unison-review-dts-play-fi-and-airplay-preamp-streams-anything.html

Auralic Aries is worth checking out I like their LDS app very much and the app is a large part of the experience.

Budget?

Rest of system?

PS Audio DS DAC MKII will let you plug in all kinds of ways. I prefer solid sate and at least two copies.