Sony used to sell a lipstick cam which had sterio michrophones built in. (CVX V3 P=PAL)
http://www.adorama.com/SOCVXV3.html
This unit had the capability to lock on to the clamshell recorder (DSR V10)so it's a small self contained unit. Alternatively you can attach a battery to the unit which will run the camera for some eight hours!
The performance far exceeds the very old 999 by a proverbial country mile. The auto white & auto exposure were quite remarkable in it's performance.
When you flick this unit on to wide angle it's damn wide.
As the fitting which connects to the clam shell also has RCA connectors you can take the video out which I have fed in to a BVW50 VTR with surprisingly good results. Alternatively Using the 50 as an audio mixer excellent audio can be attained.
This may be the answer your looking for Matt Box using the clam shell VTR is a back pack size unit which is self contained, just don't drop it