Hello,
I'm a Linux\Unix systems engineer, VMware administrator, also certified Red Hat and VMware.
Also, I have good experience in Linux administration, troubleshooting, service installing and monitoring.
If this setup will Linux Network GRE tunnel setup I can help you. If it Windows I can't help you.
This Project will take 40-60 hours maybe less maybe little more. it depends on your servers and your current setup.
so, I'm interested in your project and I can help you.
Best Regards,