BackUp From iMac To MacServer

Hi,

I wonder if any of you can help me, I am currently maintaining a mac network with 25 iMac's all running 'Leopard Snow' connected to a Mac Server that is using LDAP to pull the users from Windows AD.

The users are currently working locally and saving the work locally into a folder on the root of the Mac Hard drive.
I need to find a way of backing that folder up to the mac server, I have tried the users working from the mac server but it is very slow when all 25 users are steaming/editing videos from it.

I have looked into 'Time Machine' backing up a single folder but

Does anyone know of any good software that will allow me to backup/sync the local folder from the local hard drive to the mac server, free would be nice but don't mind paying

Thanks a lot in advance