Fondant is made for covering cakes, but can be used to make flowers... Gumpaste is made for making flowers...It can be rolled very thin so your flowers can look ver realistic. It also dries faster and stronger than fondant. Now, I do know some decorators use fondant for everything...They just add tylose to the fondant. I've never done this so I don't know how thin it can rolled with the tylose in it.
I've only made mmf once to try it so I'm not sure how it is for making things... You can buy premade gumpaste or you can buy it. Nicholas Lodge's recipe is super easy to make and to work with. It's basically egg whites, powdered sugar and tylose.