[asterisk-biz] Multi-tenant PBX Manager

[router]

Hi,
I am looking for an Asterisk Mult-itenant PBX manager. Any suggestions?
It has to allow setup of: extensions, voicemail, auto-attendants (time
related), queues, conferences.
Also, it has to permit some "modifications" in order to extend the solution
for redundancy/distributed servers (e.g.: members of the same group or queue
might be registered to different Asterisk servers, or, another example: call
local support during working days/hours in US otherwise call overseas
extensions/group/queue).

The solution doesn't have to be free, open source, but I need an evaluation
copy first, in order to decide if it can be adapted to my requirements. Web
demos are not good enough.

It looks like I don't know exactly what I am looking for, so any suggestion
is appreciated.

Thank you.