Hello Im Sourish, I'm a Linux, asterisk, network expert. I have done similar projects in the past and you can check it on my profile. I can do this for you within a day or two. I can install Windows on a centos server running qemu or a full fledged virtualization platform like proxmox.
Please let me know and we can talk further on it. You can try it with me and if you are satisfied then you can pay me. Looking forward to hear from you soon and hope to be a part of this project.
Thanks
Sourish