Hello, I'm a voip specialist with over 10 years of experience working on the TS department of a US voip company; I can install, troubleshoot and customize many VOIP devices including: softphones, ATAs, IP-phones and PBX systems like Asterisk/FPBX. I read your project description and I can certainly help you setup your PBX system with Google Voice as well as give you good suggestions/advices as needed. You may contact me through chat at any time.
Thank you.