Membership subscription plugin will help you start membership subscription for your customers with following features
1) User type manager - Now you can create your own user types with website and keyword limit.
Paypal integrated payment system is available with the plugin. Contact us to add new payment gateway to the system.
2) Website count limit for each subscription type
3) Keyword count limit for each subscription type
4) Order manager - To manage orders from customers
There are lots of features under this plugin, check above demo link to get more details about plugin.