[TriLUG] OSS Backup software and mulitple OS clients

[Roy Vestal]

I'm working with a non-profit and am trying to come up with a backup 
solution with OSS. Here are the specifics

10 Windows XP machines
1 Linux Samba Linux Server
1 Mac (OSX) client
1 Backup Server
1 NAS (for backup storage)

Backup side:
Disk backup as opposed to tape backup
Automated solution - minimal interaction as there is no sysadmin on site
Incremental/Full/Current Data Protection (In Use Files), Bare Metal 
restore a plus but not needed
Push/Pull configuration

Client side:
Client side configuration in addition to admin configuration (user 
should be able to add to what is being updated)
Client side file restore
Client side initiated backup

We need a solution that is cross platform as you can see. We want to use 
Linux (most likely CentOS) for the backup server. I've been looking at 
Amanda/Zmanda and Backula. I'd like suggestions on these or any other 
OSS solutions.

TIA,
Roy