DAW= digital audio workstation (right?) That's the way computer with special hardware for recording music are called.
Also from Digidesign is the MBox, which is basically the same as the Digi001 but with less inputs (although it has Focusrite preamps, which I think are better).
Another good option is the one made by
www.motu.com. They are connected via Firewire, which means that you can plug them to a laptop. That's great for home recording.
Those are the cards that I know best. I on Digidesign's cards one great thing is that they come with Protools LE, which is a GREAT software for recording. The downside of Digidesign is that is expensive in terms: the plugins for MOTU and CUBASE are more and cheaper, even free (VST plugs).
don't forget mics and preamps costs. And take a look at
Propellerheads Reason, great program for making music.
You can download Protools Free, which is a streamlined version of PT, with 8 tracks. You can use it without a card to see if you like it.
Cheers, Andrés