QNAP backup

[Shinta]

I'm looking for a way to backup the following devices (or data on devices) to a QNAP NAS:

• Mac OSX box
  
• Windows box
  
• Linux box
  
• iOS devices
  
• Android devices
  

I am wondering what is the best software to run on the NAS for each or all devices. I was going to setup the volume to be encrypted which would address my encryption needs.  I was hoping to pull backups rather than push them and was hoping for something that allows versioning/incremental backups.  I am not against buying a license for software and would spend up to approx $600 USD on software.

Ideally software that can centrally manage the backups and just have an agent on each device which would carry out the server's backup requests.

If there it's better to run software locally and push updates, I need something that is portable (for example on a USB key) so that the profile of what to backup as well as the software is not touching local disk.  I think that may be the tricky part.

Any solutions or recommendations?