[Asterisk-Users] SIP - Receptionist

[willy at yponeinc.com]

Hi All!
I am thinking about fork-lift-upgrading a Nortel-Meridian
key system with a * PBX driving SIP phones in the office. 
The interface to PSTN would be a fractional T1 PRI (11 lines
plus D channel). The GS phones look acceptable for most
users. The forthcoming "Sayson 480i" would work for
management types.  The receptionist, however, is currently
used seeing a backlit display - with buttons - attached to
her phone - showing all the extensions in the office, and
who's has a conversation going etc.  We believe that
autoattendant should only be used after hours ;).
Question:  How do I drive - acquire such panels with
asterisk? What are they called? who makes em?  I have seen
Monastery, but that may be too cumbersome an interface for
the relatively high call volume.
I hope I explained what I am looking for.
TIA 
WW