fwiw, I've been using the stock soundcard in my PC (Soundblaster Audigy something-or-other) to record v-o for the past 3 years and have never had a single complaint/problem. I've been running my Marshall MXL-2001 mic --> dbx 286a --> mackie 1202-vlz --> the tiny little line-in jack on said soundcard and recording into SoundForge... no glitches, no noticable noise, and I personally think my v-o that I record at home sounds better than when I record with the expensive ProTools system at work.
That said, I just ordered a Focusrite Saffire Firewire box because I'm going to start doing more extensive recording, but for a start-up situation I wouldn't completely discount on-board soundcards.