Talk to your VAR, they can give you upgrade paths for moving the data from PDMW to EPDM.
Correct, PDMW to PDMWE file migration tools do exist. They just need some variable mapping done.
There is a migration tool that works per project in PDMWW You can review the files in PDMWW and create a project(or projects) that contains the files that you want to migrate. You can migrate all versions of the files per project or just the latest version.
Did you use the change status options in PDMWW? If you did then you have to map the statuses from PDMWW to the ePDM states.
This may sound confusing but I am sure that your var can help you on these issues.