Sorry again, I meant to say "... what I know about Jamulus" .
Linux might indeed be a deal-breaker for Jamkazam - there doesn't seem to be an option to download a Linux client. There are a couple of references to it but they all seem to date from a few years ago.
Jamulus does have Linux support. There may even be a package, depending on which version you are using. If not, it's pretty straightforward to complie from source. I haven't built a client, but I did build the server code on a Raspberry Pi and it worked OK, just took a little while to compile.
B3 should work fine. If your PC has a built-in mike you could use that for voice, but there's a text chat window so it's not crucial provided that you are sighted. One of the people I play with is blind, so he doesn't have a lot of use for text chat.
Drop me a PM when you're ready, if you need help.