So I've been putting together this studio with a Mac Pro and Ableton Live. It's rockin' the Radeon 1900 video card, 3GB RAM, dual 23" HD monitors, but my question is about the sound card. To really turn this into a pro-level studio, do I need an external sound card, as described on the "DJ'ing with Apple" help page? I'm not mixing live here (with the computer anyway, I can still do that old skool analog style), and I can hear the output thru Ableton to match the trax. So what would an external sound card offer? And I tried attaching a pic of the studio, but the size was too big. As you can tell, I'm a brand new Apple user. How can I compress the file and share a view of my efforts? Thanks for your help.