Dave, the advice you gave didn't just used to be: Still is on Focusrite's page.
RME's UCX supports 3.0, but it's a bit above your $300 price point (about 5x)...
Indeed^! And can I add that "back in the day" when every fifth forum question seemed to be to do with audio problems and Fussywire! Any Firewire card bought should be JUST FW400. Not FW+USB and not FW800+FW400. And TI chipset of course.
Hah! Just noticed that the SIG card suggested IS FW800! Just goes to show that nothing is cast in stone when it comes to computers. The advice always USED to be as I stated!
Dave.