Are you changing hardware? If you keep debian, you can always
Code:
dpkg --get-selections > myselections.txt
then transfer that to the new machine and
Code:
dpkg --set-selections < myselections.txt
dselect update
apt-get dselect-upgrade
This will give you all the same programs you had installed on the old hardware.
If the hardware is the same, you can just apt-get a 64bit kernel...