Well stone the crows! it has worked.
Server in the DMZ and listening to port 80 and all appears to be working just fine. So simple, so easy, I wonder why it took so bloody long to find out.
So for anyone facing the same or similar issue the answer is...
1, make sure that you have an active firewall on your server and only open the ports that you absolutely need to.
2, use your modems configuration to set your server as a DMZ host.
3, configure apache to listen on port 80 (the default)
4, keep your server and software up to date to hopefully not end up with any security vulnerabilities.
5, play, experiment, use CMS like Wordpress (because now you can) and enjoy.
6, Remember to thank everyone who helped.... Thanks guys