Ingersoll dealers are THE place to get parts. Case stopped supporting these tractors in the mid-80's after they sold the division to Jack Ingersoll. Look in the FAQ's under "Ingersoll Dealers".
Yes, they can be converted. However, many of us prefer the word "perverted" to describe this procedure.
Why would you want to remove the very best clutch ever made and install something inferior? Go to the Library under Service Manuals/Clutch and read about servicing your clutch. Yes....there are several "wear parts" but they can be replaced individually, whereas a failed electric clutch gets replaced totally as a single piece........often for a cost that exceeds $250.00. A properly maintained EZ Clutch will outlast an electric clutch 4 times over.