R2R Ladder DACs or All in One Streamer Solutions

I am soon to own a Pass INT 25 integrated amp. I also own an Oppo 205. 

I am now searching for a separate DAC to replace/improve the DAC in the Oppo.
Budget $2k. Used preferred.

I like the R2R ladder sound and want a tube inside for a little balance with the Solid State gear.
My current source is the Oppo 205.

I am also shopping for a Streamer/Ripper/Storage device. Roon friendly and DSD capable.
Budget also $2k. Used Preferred.

It seems that the few offerings of these all in one solutions all contain a DAC.
My thought is that the DAC included will not be any better than the Oppo so it is of little use.

Has anyone been down this road lately? 

Am I missing something?

Thanks in advance for sharing your experiences!