Existing Wordpress Plugin Needs Addtional Work

We have an existing, fully functional Wordpress Plugin that we want to add some functionality too. Here is a basic overview of what we nee done. (A complete detailed list will be provided to shortlisted bidders). - Custom email entry form that works with the API from 4 different email-autoresponder companies. - Implementation of a 'slider popup'. This is a banner that 'slides in' from the top of bottom of the page. The plugin already has this feature, we want to add custom formatting so the user can select the color and transparency of the slider. Additionally, the user will be able to add a email entry form, custom text, and social media links. - Reorganization of an existing content locker. We want to display the content locker in a specific way. - Reorganization of the current popup (different than the popup) That is the basic overview. Again, specific details will be given to the 'short listed' people so that you can give a educated estimate. Please respond with your experience with Wordpress plugins, and any example you have.