Which USB audio interface?

Firstly, have a look at this thread
https://forum.audacityteam.org/t/sound-card-reviews/8375/1
which lists users’ reviews of sound cards that work successfully with Audacity.

Offhand, one unit that seems to match your requirements is the Alesis IO/2 Express, but I have no personal experience of it; I’m only looking at the specs on one supplier’s website, since the Alesis website seems to have problems at the moment.

POL