Upgrading a gas-only RV water heater to electric without eliminating the anode rod

[KevinJones]

I'm looking for an aftermarket kit for upgrading a gas-only RV water heater to electric. The problem I am having is that I have a Suburban water heater with a cast iron tank, and I don't want to eliminate the anode rod, which is what most of those kits do. There is a Briidea RV Electric Water Hybrid Heater Kit with replaceable anode rods, but as far as I can tell from searches, it is only 425 watts even for the 10 gallon model. Can you find a kit with higher wattage that would also have replaceable anode rods, or maybe the element functions as an anode rod? Or is it possible the Briidea has a larger wattage for the 10 gallon, and all of the results I have been getting are only for the 6 gallon?