I thought you should be able to do it with that plugin since it is responsive. Do they not have an option to do so? What if you try setting the width to a large number?
If that doesn’t work, there are a few premium plugins out there that can definitely work as full width. Like this one for example – http://demo.appfinite.net/ally/ here is their site – http://kreaturamedia.com/layerslider-responsive-wordpress-slider-plugin/ It’s like $15 bucks, which is very cheap considering all that it can do.