Is there a two way GMR/FRS radio system available that supports
isolated or private communication to a specific numbered handset
within a local system?

To put it bluntly, we're looking for a wireless intercom system under
$1000 that supports up to 4 relatively durable handsets with a range
of ~0.5km or more.  If an ideal system is found, we would be happy to
tip an additional $75.  PBX based solutions are not preferred due to
size, cost, and other factors.

It looks to me as if the Chatterbox FRS X2 would be your best bet:


http://www.epinions.com/content_57664704132



The Chatterbox is designed for motorcycle-to-motorcycle
communications, and has a reputation as an excellent communications
unit.

More to the point, though, the Chatterbox can be set up for 'chat
groups' within large groups of riders.  That is, you can use it to
communicate with specified recipients, rather than an entire group,
which seems to be just the functionality you're looking for.  From the
write-up at the above link:


"...the radio also offers you the ability to set up chat groups (a
smaller group within a riding group) and you have the option to set up
many differet chat groups which you can toggle in and out of easily by
using the simply and well laid out buttons on the box..."


The Chatterbox is also cell-phone compatible, so it can be used to
facilitate phone to phone communications.


I trust that's the type of system you're looking for.  But if there's
anything more I can do for you, just let me know.


All the best in the new year ahead,


David

saguratus-ga:

Unfortunately, the GMRS and FRS personal radio services may not be
used with encryption or coding of any kind, rendering their useless as
a private communication system.

http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr95.183.htm

To achieve what you are looking for, you will need to consider
licensed radio units with digital encryption; unfortunately, this will
greatly exceed the $1000 budget.

Regards,

aht-ga