Hello, I have 10 years of experience working as a level2 voip tech for a US company, I'm familiar with several sip devices and applications including softphones, ip-phones, ATAs and PBX systems like Asterisk/FPBX, I have installed, troubleshoot and customized many systems; I read your project description and I can help you build your Asterisk/FPBX with custom IVR solution, you may contact me to share more info on your special requirements and I can start this project for you.
Thank you.