I don't know if this is the right place to ask about this, but I'll give it a try.
I'm a linux user for a while now and I try to avoid opening Windows as much as possible. But for some things, I just have to. One of those things is recording. I play the guitar and I write music so I often need to record what I'm playing. Just in case it matters I'm planning to use ardour
audacity
rosegarden
hydrogen
and most of those nice programs that are widely known (linux known hehe). I need external usb sound card suggestions so I can do my thing on linux as well. Not too expensive please.
Lists of supported audio interfaces for Linux: