Extra camera? Wow. I had this thing in school where we had to make an AVP. Since we had to interview people, I was particular about the ambient sound and the environment's noise (people walking, etc).
What we did was use a laptop + an altec lansing microphone connected for audio recording. We recorded using Adobe Auditon as WAV then transferred it to the desktop video editing for synching.
The result was pretty good. It saved us a lot of time reducing noise digitally. I'll post a very short clip soon.