Hello, i am a voip engineer with more than 6 year of expertise in the field, i have worked with asterisk, 3cx, freepbx, elastix, freeswitch and most popular voip/pbx systems on the market, i can help you to make this setup and give information on how to maintain the system after install, if you are interested to talk regarding this just hit me on chat or add me on skype: montana3601