Migrating from 6.20 to 7.00 is a trivial in-place upgrade.
If you move to a new Server best do an Export of the IDB (omnidbutil -writedb), copy the Export and your Config-Files to the new Server and import it there under the same DP-Release as the source. That way you have a working fallback and a clean IDB to start from.
Don't try to force it and import to a newer release, keep it two-step as Bob suggested.
If you can take over the IP that your licenses are registered to do that. Otherwise skip the lic.dat file and migrate/upgrade your licenses to the new Host/IP during the 60-day trial period.