Under a year, milk, be it breastmilk or formula, should be the mainstay of your childs diet. Since your baby has a good intake of formula, it looks like everything is on track! Since your baby is sleeping so well, it certainly doesn't seem as though hunger is an issue, although of course, hunger isn't the only reason why babies wake, if only it were that simple!
Have you intro's any finger foods yet? Riley really enjoyed eating little pieces of cereal, toast, soft fruit etc at that age. It's so exciting to see them self feed themselves too!
There is lots of great info in the frequently asked questions section, and also feeding routines where Moms share about what their lo's eat at the top of this board. I think you'll find exactly what you are looking for there!