I decided the best way would be to order a new IP and bind it to the new website so thats its completely seperate from my torrenting.. for an extra 1 Euro a month its probably worth it.. this is how I did it with the help of Lardo.. 
1. Order new failover IP from OVH and wait for email confirmation.
2. Go to the OVH Manager > services > ip fail over > add an ip fail over and follow instuctions.
3. Login as root and use their help page OVH : IpAlias to assign the new IP to the network interface card.
4. Login to 123-Reg and direct the domain name to the new IP.
5. Move the website to a new folder on the server.
6. Add the following to /etc/lighttpd/lighttpd.conf
Code:
server.port = 80
server.bind = "<IP_OF_SERVER>"
$SERVER["socket"] == "<NEW_IP_YOU_WANT_TO_USE>" {
server.document-root = "<NEW_PATH_TO_WEBSITE>"
}
Now my website has a completely different IP to my rutorrent and if I type the ip of my server it just comes up with my 'Under Constuction' page..