Alien is a really cool tool for converting packages between different formats. It can create fairly a good DebianPackage out of an rpm. There are options you will need to use to ensure the (pre||post)inst scripts are included in the Debian package, because it defaults to turning them off for security. Off the top of my head, use 'alien -c -N <rpm-package>', but check the man page.
You can transfer one partition to another over the network roughly like this:
on source: cat /dev/hda1 || gzip || netcat -p 1234 destinationhost.somewhere.com
on destination: netcat -l -p 1234 || gunzip > /dev/hda1
(set the destination to listen before executing the command on the source machine)
Obviously the destination partition needs to exist and be the correct size. You can also transfer a root partition this way if you boot the machine with a bootable Linux such as Knoppix or tomsrtbt. This is a great way to clone a machine if you need to do so. Obviously you might have problems if you have very different devices etc.