At 7 months of age, you can move over to an adult food within the next few weeks or months, whenever you are comfortable with it.
I am a big fan of some of the commercial foods. I like Eukanuba and Science Diet but some of the other brands are just as good. If you can get it at the grocery store, it's usually not very high quality.
I do not think that you need to avoid corn, lamb or rice. I would phase these things out if your dog develops an allergy but I would not worry about it until then.
And FYI- She's going to be hyped up no matter what you feed her. It's a trait of the breed.
Let me know if you still have questions.