Is there any way to use one of the existing filters to only import products with a ean number?
Yes - the standard "Drop Record" filter will do this if the text box configuration page is left empty. Just add teh new filter to the EAN field, save, and re-import.
Great,just tried works OK, however just noticed some feeds have 0 if no ean number, any way to prevent this importing.
No problem - if you sequence a second "Drop Record" filter after the first empty one with just "0" in the text box on the configuration page that should do the trick...