Integrate Aweber, constant contact, mail chimp, icontact, get response etc into my wordpress plugin

I'm developing a landing page plugin for wordpress. I would like to have the option to allow users to select from various email service providers in the back end of the plugin. The plugin is set up using WP custom post types. I'm also using meta boxes on my post type. I would like a email settings meta box attached to my custom post type that allows the user to select which email service they would like to use to capture the leads. Services I want integrated are Aweber, constant contact, mail chimp, icontact, get response, wysija, and mymail. Only bid if you have done this type of integration before. Thanks!