If you're going to clone a Mini itself, just boot into the installer and run Disk Utility, save it to an external drive, or for that matter if it is a RunCore then just plug it into the USB port and image it directly. Then just boot from DellMiniBoot/DellEFIBootMaker and run DellEFI again afterward. However, copying an install to another Mini is illegal UNLESS (that's more of a maybe) the other person already owns a copy of Leopard and just doesn't want to go through the painless install process.
As for installing from a Mac, yes you can by installing to a flash drive/RunCore and then imaging/installing (respectively) to the Mini. But cloning a Mac? No. Again, if you have a retail copy of Leopard that is set aside for the Mini, then I guess it could be technically but I don't see any advantage and it would seem to be more work from my point of view.
Family Pack? I guess that works, but it needs to be YOUR family pack, if you catch my drift. Just remember, whatever copy you install/image over MUST BE LEGIT and must be yours. No torrents, no OEM discs (aka the ones that came with you MacBook/iMac/Mac Pro/Mac Mini/whatever) and no "friend's disc" or copies. If it matches any of those criteria then it IS NOT LEGAL. (And please do not turn this into another legality/EULA threads, I'm just answering the questions responsibly.) I've given you what I know, just be smart about it.
Edit: Ah, michael.lauden, we were writing at the same time. Yes, that is more reasonable, I thought you were trying to just copy EVERYTHING. Your situation makes more sense, and yes iLife should fit. Funny we both mentioned the EULA somewhere...