Sound card or Zoom portable studio?

[alamsemu]

I want to do some decent-but-nothing-fancy home recording. Say I have a good mic and a software to start with, which one would you recommend getting next, a decent sound card (like M-Audio fast track), or a portable recording device (like Zoom PS-04)? I will record mainly guitar tracks, and will be using my laptop.

I appreciate your input very much. Thanks.

Cheers...