Call Jake at Am-Dig. He has some that will work for you. He has an old school Marantz that is very finicky with media, and has been able to keep it going w/o too much trouble. He told me last week that they had just gotten in a new batch of media that's certified to work with the single speed burners. I'm not sure what the cost is, but it is worth a call. He's in the office today, but won't be around again until Monday due to Yom Kippur.
Peace,
Dave
1-888-usa-dats