I would recommend using USB from any streamer into a Denafrips DAC. These DACs reclock the input data. If you use a synchronous input (anything other than USB), you risk FIFO overflow or underflow which will cause audible glitches.
I currently own the Terminator Plus and owned a Terminator previously.
I’d recommend focusing first on getting a good USB streamer, and then if you have a Denafrips DAC with clock outputs, you can consider a DDC such as the Gaia. If your DAC doesn’t have clock outputs, I think you are better off skipping the DDC and using USB directly into the DAC.