Toto Supreme problems...

Hi everyone. I have a Toto Supreme with the Power Gravity system. The fill valve seems to be broken as it is leaking heavily from the top, eventhough I cleaned it multiple times. Now, can I buy a Korky QuietFill valve at the local hardware store or do I need to buy an OEM Toto replacement valve? Also, while I am at it, where do I find a replacement flapper? Can I buy a Korky flapper or do I need to buy an OEM replacement flapper from Toto?

Thanks.
Gavin

Thank you very much! I replaced my old fill valve with the Korky QuietFill and everything works great now. I also replaced the flappers. Thanks again.