How to be more assertive and Charismatic with a stutter?

How to be more assertive and Charismatic with a stutter? With a stutter I feel like I walk a fine line between saying what I want to with a monotone voice and not stutter. Or come off as awkward autistic with a crazy block if I really try to put emotion into my speech and try speaking naturally. Anyways I seriously feel it kills alot of my charm and assertiveness What do I do? I feel there isn't a way I can be assertive or charismatic with a stutter. I want to exude that charm and assertive presence that someone like say Jon Stewart or Terry Crews have. I guess I'll never be 'that' good but I feel there's some way I can get pretty damn close. Are there any people out there on that level who stutter?