Parking for multi-tenant office

We have been running Asterisk for 2 years now in our office and have had many problems. The main problem though is that we run 3 businesses on the one floor which come into a central reception area. We would like to park calls for these businesses into specific parking spots which we could retrieve on any phone. We use Snom 320 & 300 phones mainly around the office.

We have tried valet parking and another similar patch for Asterisk 1.2 (which is what we are running).
Refer: … king_1.2.c

We would like to be able to park and pickup a call with a single button per parking spot for each company. These buttons on the snom320 should light up when there is a parked call on there. We are 90% there, the only problem is we have two buttons for each parking spot, and if you park two calls into the same parking spot the system crashes the parking and all parked calls are lost in the system.

We don’t want to have automatically allocated numbers for parking as that is hard to track as we have multiple receptionists running around and to remember which numbered parking spot was for which company would be impractical. Also we want to drive this all through the phone.

The old analogue system (which this Asterisk phone system replaced) could perform these tasks without a problem. We run the same 8 analogue lines as we used to use into the Asterisk box. On the old system these lines showed up on everyones phone when a call come in and anyone in the office could answer that call. You could tell if it was on park as the button for the phone line flashed, you could also tell which company it was for by the phone number on that button. It was an easy system.

Is there an easier way of doing this?
Can we map Zap channels to buttons on each phone and have them update the light when the call is active or flash when on hold?
Does Asterisk 1.6 have new features in the parking to deal with multi-tenant offices?
Is there any better plugins we should know about?