Here is a tutorial on how to put a RTMP server using nginx on a Linux box. It's written for Debian, but you can follow it on any distro, just changin the first command according to your distro package manager & repositories.
According to how many people will see your broadcast, video & audio quality, etc, you may need additional bandwidth from OVH. Check the prices here:
https://www.ovh.co.uk/dedicated_serv...th-upgrade.xml