IMO, I'd go with a large breed puppy food. I figure people have been paid a lot of money to do research on food and nutrition, I don't have a degree in that so I'd go with what has been studied.
Sounds like you have a large female. When our pup was in the 4 month age range she was in the 40's lb range. She is 90lb at 4 years old, not overweight but our vet would like to see her at 85lb.