Do you need a customization of the plugin so it will suit your needs? In that case, we strongly recommend you to use the customization service of WP·Kraken.
WP·Kraken is used by many top WP authors like: WPBakery, ThemePunch, MuffinGroup, SevenSpark, GoodLayers. To name just a few. They only use in-house developers and thus have full control over the quality of the work.
Quite important: It’s cheap! And the cool thing is that if you are not satisfied with their service or they don’t meet your guidelines, you will get your money back ! It’s 100% guaranteed.