i think this weekend if i have the right wires i'll try a test run and see what i can do and then go from there. i'll post back here if i'm having any issues with it. thanks everyone for your input. any other ideas are appreciated too.

Is it possible to use multiple inputs? do you have any way to? cuz that sounds like the only way you could do it.
like, you'd need SONAR for the actual editing, whose line out goes to some recording program. then separately you'd need to record the voice over. 
perhaps I'm a little hazy. just that this sounds like the process you're trying to do.

i haven't done a full runthrough test using a 2nd computer yet, but i did try recording 2 inputs in sonar (a guitar and a mic, so i'm sure i can do a computer through line-in and a mic) and it worked great recording to 2 separate tracks.

so when i get a chance in the next week or so i'm gonna try hooking a line out to a line in on another computer and try an actual run through of this idea and see what happens.

i'll report back :-)

If you have an external soundcard, and onboard soundcard you could:

Record Sonar as normal through external soundcard
Record voice using Audacity with a mic plugged in to your onboard soundcard, like a webcam, headset, etc