Below are the 3 WP plugins for affiliate that can help you with your affiliate marketing.
1) Duplicator (
http://wordpress.org/extend/plugins/duplicator) : If you are the type that create a lot of wordpress affiliate websites, you probably find you spend a lot of time tweaking your theme and settings with each initial set up.
2) Amazon Affiliate Link Localizer (
http://wordpress.org/extend/plugins/amazon-affiliate-link-localizer): This is a very powerful plug-in. All you need to do is to install and activate the plug inside your wp-admin dashboard and then add your Amazon affiliate ID in the settings area. Once this is set up, any time you add a link to an Amazon product in your posts, the plugin automatically makes it your affiliate link and it directs the user to the proper Amazon site according to their location.
3) Pretty Link Lite (
http://wordpress.org/extend/plugins/pretty-link): This is also one of my favorite wordpress plugin that I always use for my affiliate websites. this plugin allows you to take long and nasty-looking affiliate links and easily turn them into “pretty links†that look like they are links within your site and you can also use it to track clicks on each link you create.
For the recurring monthly payments, you can use - online payments and subscription billing (paywhirl.com).