I've been researching eCommerce payment gateways and service offerings, but I'm an eCommerce novice, so please excuse my ignorance.

I wish to set up an eCommerce solution with the following requirements:

1. User "subscribes" to the service on a yearly basis. This service includes a single product subscription for a set amount (let's say $50/yr).
2. User can "subscribe" to additional product services for a lesser rate per year (let's say $25/yr).
3. I will need to store a product service unique Id of some sort for each product subscription the user subscribes to in order to show them product unique information. I also need to prevent duplicates...for example, user can subscribe to product ABC and XYZ, but not 2 of ABC.

Is PayPal the best solution for something like this? Is there a better solution? Any assistance is greatly appreciated, even if just links to specific tutorials or examples.

Update: It looks like Chargify could be the perfect solution.