I have looked around for something like the flower cutter shown above. Am I just not seeing it? Do they come in a graduated set?

That flower was most likely done with the cutters in the Wilton gumpaste kit. The book that comes with the kit is not very useful, but the flower cutters are worth the money (as long as you find a coupon )

It has different sizes of that shape of flower. The smaller ones have to be pushed out of the cutter with a little stick but if you do it in the center it doesn't deform the flower.

TExas Rose is exactly right... during my internship @ Pink Cake Box (where that cake is from) I must have cut out HUNDREDS of those flowers lol. They are sort of a signature of her designs. It is a small green plastic wilton flower cutter that you can purchase at nearly any craft store.

Any five petal cutter in the size that you want works for that..
Here is a few of them
http://www.globalsugarart.com/search.php?search=five+petal

Wilton has them too
Edna