What do you think of the Audinate Dante AoIP dongles?
Unfortunately, you will need a networked environment (OS agnostic) but will not be included in the total cost of both @$350.
I think they have both a USB and an AES dongle but it will max out at 16bits.
SMSL SD9 (was $400) accepts two USB2.0 and a USB-Audio as inputs and provides AES/EBU as well as I2S and coax outputs.
The older SMSL DP5 and the Gustard-16/18/26 series accepts USB and AES/EBU ONLY as inputs.