Hello,
I can do this job for you, but I do not work with Elastix. I have found many problems with Elastix, and I install FreePBX in all of my clients. I can install a self contained FreePBX with Linux and CentOS on a VPS and configure Zoho phonebridge trial account to work with it. After completion, I will deliver documentation of what I did and how to replicate it on a new VPS. I will have to do this on Sunday and finish Monday. Let me know if I may be of assistance. Thank you.