Fellas, i've downloaded a few more zombie maps and have been giving them a bit of a run in SP and i gotta say, they are AWESOME!! Will have to get another map pack set up and we'll have to give them a run. Dead easy to instal them and easy to set up. Something we should definately get going imo... I'll get it sorted and get some instal instructions together as well. I'll figure out where to host them and we'll get a sesh going.
I'll post back details as soon as i get the chance to get it sorted.