hi,
it seems like an interesting project!.
kindly let me know if you have your asterisk setup already or not,
if yes which version are you using and which freepbx (if any).
around how many DIDs do you plan to have and how are you going to get the DIDs connect to the Asterisk (via SIP trunk or DAHDI FXO cards).
kindly let me know if we can some chat about your project to be able to understand it better.
regards,