PBX in a flash or similar

Closed - This job posting has been filled and work has been completed.

Job Description

Im currently using polycome phones hoasted by fonality. I wold like to switch to pbx in a flash using google voice or similar to eliminate my monthly costs.
Im not sure about what is, and isint possible to do, so i need some expert help.
I need direction in choosing a system, and then setting it up.

Whats needed:
around 20 users (minimum of 10 lines that can be used at once).
calls to us (canada) and option for international.
in office intercom system between phone extensions.
other features are a bonus.

Skills: pbx