Bannie I agree with pkukid. I also have classical PKU, and I have been on Kuvan for almost two years now. Like I already posted before I began Kuvan I was allowed 300 mg of phe, which is about half of what you are allowed. Some people who have classical PKU respond, and others do not. It really just depends on the individual person.
When you finally have the opportunity to try Kuvan I would suggest at least giving it a try. You might be surprised! I know I was, because I was told I probably would not respond, but I definitely did.