Cleaning rust stains from refinished tub?

I'm thinking of having an old cast iron tub refinished with, oh, say, "Miracle Method", or some such. We have high iron in our water and all the old porcelain fixtures are quite orange. Has anyone lived with a refinished fixture and this type of water? How many showers did you take before the epoxy paint, or whatever it is they use, was hopelessly stained orange again?