How do I create backup images of Windows and Linux Servers?

I am looking for the answer to this question.  Does anyone know the answer?

We have a small office network with four Windows 2003 servers and two Gentoo Linux servers.   What is the best software tool for me to make complete images of the hard drives of these machines?  Everything is working great and I would like to know if we had a catastrophic hard drive failure, I would not have to recreate the machines from Backups (done daily to Tape and HD) and OS install disks.  All machine have either mirrored or Raid 5 SATA drives.  We use Symantec backup exec for the backups.  There is probably at total of 500 GB of data including all the OS install across all the machines.

Is there a cost effective way to image these drives and store the images in case of emergency?  Also, is it possible to make images that could be run virtually in case of emergency?  Do any of the tools have a way to update the images automatically in the future?

thanks in advance,