Yup
That kinda depends on your belief system, but whichever is cheapest and connects to your dac in the way that allows for the most formats, or whichever fits within your ability to do a bit of stuff by yourself, your budget and your beliefs. None interfere with the signal, some might transmit electrical noise to your DAC if you believe people who believe that’s audible on the analog output.
Assuming you want to do USB, which you probably do, people seem to like, in order of price, RaspPis with Ropieee, USBridges, *Rendus, and the SOTM offering. There’s a whole bunch of others that cater to different aesthetic tastes, functional desiderata and belief systems, all the way up to DCS’s $4000 network bridge (and certainly beyond).
(and if you end up going with the X26, check with Allo that the Gustard is supported).
Yup.