How to capture to file two (web) cameras synchronously

I need to synchronously capture video and audio from two web cameras, to a single encoded/compressed file. If possible the video/audio can be held separate in the encoded file, but if it is easier so, they could be also merged into one recording, for instance as a single video, where the left half-side of the recording is from camera A and right to from camera B, with the left audio channel from Camera A and right from camera B. The synchronization does not necessary be frame-to-frame accurate, if easier, it can be for instance ~100 ms accurate…
How to do this? If any how possible, using more or less standard web cameras, windows APIs, or free video libraries, or at least cheap video libraries (up to few hundred $)? Of course, playing the recorded video/audio is also necessary
To be more specific, it would be perfect to know how to do the following steps:
a)      Initialize which two cameras to use, which resolution, and codecs for video and audio
b)      Initiate/ stop synchronous video and audio recording from both cameras
c)      Combine the two videos to a single one, with left side from camera A and right from B, also with audio merging
d)      Writing an overlay text (date and time stamp) on both sides of the composite video
e)      Saving the encoded and compressed video to a file
f)      Playing the file afterwards