fleschler
Sure you can get really good streamer for well under $1,000, that you can use with your Poseidon. Buy a used BlueSound Node 130 (not 2 or 2i) for about $250, and add a used Denafrips Iris DDC for about $350 to $400.
The Node 130 only outputs via USB (which you could also send direct to the Poseidon) into the Iris. The Iris does it's magical DDC stuff, and then will allow AES/EBU, optical, RCA, and I2S to the Poseidon (I know the Poseidon does not accept I2S)
As long as you want very good, and not state of the art, this combo will work really well; and the Node has a terrific interface.