How to push/restore/install an InstaDMG image many restrictions

Hi All, I am hoping this is an okay place to ask this question as well. I am enjoying the ability of creating the InstaDMG images (and I assume they are all good), but I do not really understand how to place it into a partion or mac. The main reason why is we have many restrictions. We do not have an OSX Server, and will not be allowed to get one. I believe that eliminates a good majority of options (NetRestore, Deploy Studio, and others). We are also not allowed to allowed to purchase any new software (at least at this time). What we have. 2 ARD Task Servers which are actually just running standard OSX 10.5 (not server). We have multiple desktops and laptops that are all currently running the latest 10.5 with software. We have a few firewire drives. We have access too many Windows Servers (which I can not see helping). Is there a way to push the InstaDMG from the same machine the ARD Task Server as is to the other mac's though out our environment? I assume "no". I am pretty sure that there is a way to put the image on the firewire drive and push/restore the image from there, but I do not understand how to do that. Do I just need the .DMG image(s) on there (can I have more than one?)? Does the firewire drive need to be bootable on its own? Once I have the drive the way it needs to be. What do I need to do? Can you boot from the machine in 10.5, and use Disk Utility to overwrite itself with 10.6? Any help, or links on this type of how to would be great. Thanks, Steven Stuart