I am looking to set up a monitoring system for a research clinic
(don't worry, we get consent before taping anything).  We have 4 to 6
rooms (approx 8' by 8')where we need to be able to record a least
audio or audio/video.  Our current system involves inexpensive tape
recorders that cost $30 to $50.  The problem with those is the audio
quality is really bad.  We have also tried including a Realistic PZM
microphone, which did significantly improve the sound quality.  The
problem with this is that these microphones require people to turn
them on each time (which they forget to do), or they forget to turn
them off, the battery runs down, and then they don't work either.  The
length of a typical recording session is 50 minutes, but sometimes
goes as long as 2hours.  It is feasible for us to change/turn over
tapes if necessary.  The output needs to be something that is user
friendly (i.e., taping to a tiny camcorder tape wouldn't work).

What I would like someone to run down for me are the various options
we could use, the cost associated with each, and the pros and cons. 
The options we are currently looking at are: audio/video,
cassette/vcr/cd/dvd, and type of microphone.  The current options we
are looking at include a high end tape recorder with a microphone, a
video camera with a vcr, something like the Teraoptix Terapin
stand-alone CD video and Audio recorder with a microphone, or the
Terapin with a camera.  Someone also mentioned a RDS preamplifier
stick-on unit would be needed to connect the PMZ microphone to the
Terapin, but I've never figures out the purpose/necessity of that.

Ideally, this needs to be relatively user friendly (for people who
can't remember to turn off a microphone), but produce a high quality
sound/picture.  I think my boss is leaning a bit more towards video,
but he does want audio options as well.  If anyone knows of a PMZ
microphone that doesn't need a battery turned off and on every time,
that would be a great bonus.  Please let me know if you need any
additional clarification.  I will provide a tip for exceptional
answers.  Thanks.