Don’t need a dedicated Ethernet card really. Your Ethernet cable should match your router’s port speeds. If you use cat 5 on 1 Gig ports you can have degraded and inconsistent performance. Having said that, 100 MBPS is way more than any streaming service needs, but most routers have at least 1 Gig ports. If your router has 10 Gig ports you must use cat 6a or better.
Shielded is preferred IMHO to minimize chance of radiating to your interconnects.
So from wall to modem to router to streamer to dac, correct?
Often you have a switch near your streamer to accommodate your TV, Roku, etc. as well, so:
Modem --> router --> switch --> streamer --> DAC
If your modem has a coaxial input consider an exterior gas discharge surge protector, and an Ethernet isolator near the streamer. I’m particularly obsessive about surge protection being in a lightning prone area so I use both. Ethernet isolators are particularly good at the end of 30’ or longer Ethernet runs to reduce induced surges breaking through to downstream gear.