You can keep your current OS, Casper. No problem with it.
When OVH will send you the e-mail, they will give you the information to connect to your server via SSH and via RDP. A remote desktop client allows you to access your server as if you were in front of it (with the nice windows graphics and everything :)).
If you think you won't be able to do the setup, do not hesitate to send me a PM. I can install uTorrent, its webui and configure everything. I already setted up a few OVH servers for FST members.