I started our son on a sippy cup when he was that age and he became a sippy cup champ - he gave up bottles willingly on his own by the time he was one and we were thrilled! Also, I don't see a problem with formula in a sippy cup. She'll be expected to drink milk from a sippy cup and it's essentially the same thing, right? Just don't let her have it in the crib to fall asleep.
As for cups, we had a lot of success at that age with the disposable "Take and Toss" cups made by the First Years. You can get a pack of 6 or so for about $3 at Target. The ones made for 6 months and up are 4 oz. and have ridges on the side for easy gripping. We still only use this brand, but the straw cups now. Other sippy cups are so expensive and have so many annoying parts, these cups are great.
If you use Avent bottles, Avent makes a decent sippy cup with handles for little ones, but I've found that they can leak.
I'd give her the formula while you give her "lunch" (baby food) in her high chair. Don't expect her to drink right away, but if it becomes the routine that it's there each day, she'll hopefully get curious and figure it out. Good luck!