Here are some ideas for new skins on the server. Also, I think regular players should have the chance to choose skins for themselves so I'm throwing in some regular skins for admins AND for players (if you will allow us at least a few of them). Links to download them are next to the names.

Zombies:
Bloodsucker - download


Chainsaw - download


Undead - download


Admin/players:
Crysis Nanosuit - download


Umbrella soldier - download


Tau Commander - download


Fat nurse - download